getmail configuration (version 4)
Author: Charles Cazabon
Description: Configuration instructions for getmail version 4
Keywords: getmail configuration, getmail 4 configuration, POP3, IMAP, SSL, domain mailbox, multidrop, fetchmail replacement, message filtering, maildir, mboxrd, MDA

# getmail documentation

This is the documentation for getmail version 4. Version 4 includes numerous changes from version 3.x; if you are using getmail version 3, please refer to the documentation included with that version of the software.

getmail is Copyright © 1998-2009 Charles Cazabon.

getmail is licensed under the GNU General Public License version 2 (only). If you wish to obtain a license to distribute getmail under other terms, please contact me directly.

# Table of Contents

- getmail documentation
- - getmail documentation
  - - Features
    - Differences from previous versions
    - Requirements
    - Obtaining getmail
    - Installing getmail
    - getmail mailing lists
- getmail configuration
- - Configuring getmail
  - - Creating a getmail rc file
    - - Parameter types and formats
      - - string
        - integer
        - boolean
        - tuple of quoted strings
        - tuple of integers
        - tuple of 2-tuples
      - Creating the [retriever] section
      - - What is a "multidrop" mailbox? How do I know if I have one?
        - Common retriever parameters
        - SSL Client Parameters
        - SSL Certificate Validation and Server Parameters
        - SimplePOP3Retriever
        - BrokenUIDLPOP3Retriever
        - SimpleIMAPRetriever
        - SimplePOP3SSLRetriever
        - BrokenUIDLPOP3SSLRetriever
        - SimpleIMAPSSLRetriever
        - MultidropPOP3Retriever
        - MultidropPOP3SSLRetriever
        - MultidropSDPSRetriever
        - MultidropIMAPRetriever
        - MultidropIMAPSSLRetriever
      - Retriever examples
      - Creating the [destination] section
      - - Maildir
        - Mboxrd
        - MDA_external
        - MultiDestination
        - MultiSorter
        - MultiGuesser
        - MDA_qmaillocal
      - Creating the [options] section
      - - [options] example
      - Creating the [filter-something] sections
      - - Filter_classifier
        - Filter_external
        - Filter_TMDA
        - [filter-something] examples
      - getmail rc file examples
  - Running getmail
  - - Commandline options
    - Using getmail as an MDA
    - - Using the getmail_maildir MDA
      - - Example
      - Using the getmail_mbox MDA
      - - Example
    - Using getmail_fetch to retrieve mail from scripts
- getmail troubleshooting
- - Troubleshooting problems
  - - Error messages
    - Warning messages
    - Unexpected Behaviour
- getmail frequently-asked questions (FAQs)
- - Frequently-Asked Questions (FAQs)
  - - About getmail
    - Configuring getmail
    - How do I …
    - Using getmail with other software
    - I think I found this bug in getmail …

# Configuring getmail

Once getmail is installed, you need to configure it before you can retrieve mail with it. Follow these steps:

1. Create a data/configuration directory. The default is $HOME/.getmail/. If you choose a different location, you will need to specify it on the getmail command line. In general, other users should not be able to read the contents of this directory, so you should set the permissions on it appropriately.

       mkdir -m 0700 $HOME/.getmail

2. Create a configuration file in the configuration/data directory. The default name is getmailrc. If you choose a different filename, you will need to specify it on the getmail command line. If you want to retrieve mail from more than one mail account, you will need to create a separate rc file for each account getmail should retrieve mail from.

## Creating a getmail rc file

The configuration file format is designed to be easy to understand (both for getmail, and for the user). It is broken down into small sections of related parameters by section headers which appear on lines by themselves, enclosed in square brackets, like this:

    [section name]

Each section contains a series of parameters, declared as follows:

    parameter_name = parameter_value

A parameter value, if necessary, can span multiple lines. To indicate that the second and subsequent lines form a continuation of the previous line, they need to begin with leading whitespace, like this:

    first_parameter = value
        first parameter value continues here
    second_parameter = value

You can annotate your configuration files with comments by putting them on lines which begin with a pound sign, like this:

    first_parameter = value
    # I chose this value because of etc.
    second_parameter = value

Each rc file requires at least two specific sections. The first is retriever, which tells getmail about the mail account to retrieve messages from. The second is destination, which tells getmail what to do with the retrieved messages. There is also an optional section named options , which gives getmail general configuration information (such as whether to log its actions to a file), and other sections can be used to tell getmail to filter retrieved messages through other programs, or to deliver messages for particular users in a particular way.

### Parameter types and formats

Several different types of parameters are used in getmail rc files:

- string
- integer
- boolean
- tuple of quoted strings
- tuple of integers
- tuple of 2-tuples

Each parameter type has a specific format that must be used to represent it in the getmail rc file. They are explained below. Each parameter documented later specifies its type explicitly.

#### string

Specify a string parameter value with no special syntax:

    parameter = my value

#### integer

Specify an integer parameter value with no special syntax:

    parameter = 4150

#### boolean

A boolean parameter is true or false; you can specify its value with the (case-insensitive) words "true" and "false". The values "yes", "on" and 1 are accepted as equivalent to "true", while values "no", "off" and 0 are accepted as equivalent to "false". Some examples:

    parameter = True
    parameter = false
    parameter = NO
    parameter = 1

#### tuple of quoted strings

A tuple of quoted strings is essentially a list of strings, with each string surrounded by matching double- or single-quote characters to indicate where it begins and ends. The list must be surrounded by open- and close-parenthesis characters. A tuple may have to be a specific number of strings; for instance, a "2-tuple" must consist of two quoted strings, while a "4-tuple" must have exactly four. In most cases, the number of strings is not required to be a specific number, and it will not be specified in this fashion.

In general, a tuple of quoted strings parameter values should look like this:

    parameter = ('first string', 'second string',
        "third string that contains a ' character")

However, tuples of 0 or 1 strings require special treatment. The empty tuple is specified with just the open- and close-parenthesis characters:

    parameter = ()

A tuple containing a single quoted string requires a comma to indicate it is a tuple:

    parameter = ("single string", )

#### tuple of integers

This is very similar to a tuple of quoted strings, above, minus the quotes. Some examples:

    parameter = (1, 2, 3, 4, 5)
    parameter = (37, )
    parameter = ()

#### tuple of 2-tuples

This is a tuple of items, each of which is a 2-tuple of quoted strings. You can think of this as a list of pairs of quoted strings.

    # Three pairs
    parameter = (
        ("first-a", "first-b"),
        ("second-a", "second-b"),
        ("third-a", "third-b"),
        )
    # One pair
    parameter = (
        ("lone-a", "lone-b"),
        )

### Creating the [retriever] section

The retriever section of the rc file tells getmail what mail account to retrieve mail from, and how to access that account. Begin with the section header line as follows:

    [retriever]

Then, include a type string parameter to tell getmail what type of mail retriever to use to retrieve mail from this account. The possible values are:

- SimplePOP3Retriever — for single-user POP3 mail accounts.
- BrokenUIDLPOP3Retriever — for broken POP3 servers that do not support the UIDL command, or which do not uniquely identify messages; this provides basic support for single-user POP3 mail accounts on such servers.
- SimpleIMAPRetriever — for single-user IMAP mail accounts.
- SimplePOP3SSLRetriever — same as SimplePOP3Retriever, but uses SSL encryption.
- BrokenUIDLPOP3SSLRetriever — same as BrokenUIDLPOP3Retriever, but uses SSL encryption.
- SimpleIMAPSSLRetriever — same as SimpleIMAPRetriever, but uses SSL encryption.
- MultidropPOP3Retriever — for domain mailbox (multidrop) POP3 mail accounts.
- MultidropPOP3SSLRetriever — same as MultidropPOP3Retriever, but uses SSL encryption.
- MultidropSDPSRetriever — for domain mailbox SDPS mail accounts, as provided by the UK ISP Demon.
- MultidropIMAPRetriever — for domain mailbox (multidrop) IMAP mail accounts.
- MultidropIMAPSSLRetriever — same as MultidropIMAPRetriever, but uses SSL encryption.

#### What is a "multidrop" mailbox? How do I know if I have one?

Some ISPs, mailhosts, and other service providers provide a mail service they refer to as a "domain mailbox" or "multidrop mailbox". This is where they register a domain for you, and mail addressed to any local-part in that domain ends up in a single mailbox accessible via POP3, with the message envelope (envelope sender address and envelope recipient address) recorded properly in the message header, so that it can be re-constructed after you retrieve the messages with POP3 or IMAP. The primary benefit of this is that you can run your own MTA (qmail, Postfix, sendmail, Exchange, etc.) for your domain without having to have an SMTP daemon listening at a static IP address.

Unfortunately, a lot of what is advertised and sold as multidrop service really isn't. In many cases, the envelope recipient address of the message is not properly recorded, so the envelope information is lost and cannot be reconstructed. If the envelope isn't properly preserved, it isn't a domain mailbox, and you therefore can't use a multidrop retriever with that mailbox.

To determine if you have a multidrop mailbox, check the following list: if any of these items are not true, you do not have a multidrop mailbox.

- the mailbox must receive one copy of the message for each envelope recipient in the domain; if the message was addressed to three local-parts in the domain, the mailbox must receive three separate copies of the message.
- the envelope sender address must be recorded in a header field named Return-Path at the top of the message. If the message (incorrectly) already contained such a header field, it must be deleted before the envelope sender address is recorded.
- the envelope recipient address must be recorded in a new header field. These may be named various things, but are commonly Delivered-To, X-Envelope-To, and similar values. In the case of messages which had multiple recipients in the domain, this must be a single address, reflecting the particular recipient of this copy of the message. Note that this field (and the envelope recipient address) are not related to informational header fields created by the originating MUA, like To or cc.

If you're not sure whether you have a multidrop mailbox, you probably don't. You probably want to use SimplePOP3Retriever (for POP3 mail accounts) or SimpleIMAPRetriever (for IMAP mail accounts) retrievers.

Specify the mail account type with one of the above values, like this:

    type = typename

Then, include lines for any parameters and their values which are required by the retriever. The parameters and their types are documented below.

#### Common retriever parameters

All retriever types take several common required parameters:

- server (string) — the name or IP address of the server to retrieve mail from
- username (string) — username to provide when logging in to the mail server

All retriever types also take several optional parameters:

- port (integer) — the TCP port number to connect to. If not provided, the default is a port appropriate for the protocol (110 for POP3, etc.)
- password (string) — password to use when logging in to the mail server. If not using Kerberos authentication -- see below -- getmail gets the password credential for the POP/IMAP server in one of the following ways:
  1. from the password configuration item in the getmailrc file
  2. on Mac OS X only, from the OS X keychain
  3. on systems with Gnome keyring support, from the default Gnome keyring
  4. if not found via any of the above methods, getmail will prompt for the password when run
  To store your POP/IMAP account password into the Gnome keyring, ensure the password is not provided in the getmailrc file, and run getmail with the special option --store-password-in-gnome-keyring; getmail will run, prompt you for the password, store it in the Gnome keyring, and exit without retrieving mail. If this option is not recognized, your Python installation does not have Gnome keyring integration support, or Gnome indicates that the keyring is not available. If using the OSX keychain on 10.9 "Mavericks" (or later, presumably), some additional steps may be necessary to make the password available to getmail via the keychain. See this posting to the getmail users' mailing list by Alan Schmitt for details.

All IMAP retriever types also take the following optional parameters:

- mailboxes (tuple of quoted strings) — a list of mailbox paths to retrieve mail from, expressed as a Python tuple. If not specified, the default is to retrieve mail from the mail folder named INBOX. You might want to retrieve messages from several different mail folders, using a configuration like this:

      mailboxes = ("INBOX", "INBOX.spam",
          "mailing-lists.model-railroading")

  Note that the format for hierarchical folder names is determined by the IMAP server, not by getmail. Consult your server's documentation or postmaster if you're unsure what form your server uses. If your mailbox names contain non-ASCII characters, ensure that your getmailrc file is stored with UTF-8 encoding so that getmail can correctly determine the unicode character names that need to be quoted in IMAP's modified UTF-7 encoding; if you do not do this, the mailbox names will not match what the server expects them to be, or will cause UnicodeErrors when attempting to load your getmailrc file. As a special case, in getmail version 4.29.0 and later, the unquoted base (non-tuple) value ALL (case-sensitive) means to retrieve mail from all selectable IMAP mailboxes in the account. To retrieve messages from all mailboxes, you would use:

      mailboxes = ALL

- use_peek (boolean) — whether to use PEEK to retrieve the message; the default is True. IMAP servers typically mark a message as seen if PEEK is not used to retrieve the message content. Versions of getmail prior to 4.26.0 did not use PEEK to retrieve messages.
- move_on_delete (string) — if set, messages are moved to the named mail folder before being deleted from their original location. Note that if you configure getmail not to delete retrieved messages (the default behaviour), they will not be moved at all.
- use_kerberos (boolean) — whether to use Kerberos authentication with the IMAP server. If not set, normal password-based authenticaion is used. Note that when you use Kerberos authentication, it is up to you to ensure you have a valid Kerberos ticket (perhaps by running a ticket-renewing agent such as kstart or similar). This feature requires that a recent version of pykerberos with GSS support is installed; check your OS distribution or see http://honk.sigxcpu.org/projects/pykerberos/" for details.

#### SSL Client Parameters

All SSL-enabled retriever types also take the following options, to allow specifying the use of a particular client key and client certificate in establishing a connection to the server.

- keyfile (string) — use the specified PEM-formatted key file in the SSL negotiation.
- certfile (string) — use the specified PEM-formatted certificate file in the SSL negotiation.

#### SSL Certificate Validation and Server Parameters

All SSL-enabled POP and IMAP retriever types also take the following options, allowing you to require validation of the server's SSL certificate, or to check the server's certificate fingerprint against a known good value, or to control the specific SSL cipher used during the connection.

Note: using these features, including server certificate validation, requires using Python 2.6 or Python 2.7 or higher with getmail. If you use an earlier version of Python, these features will not work, and no server certificate validation will be performed. Also note that these features are not currently implemented for SPDS retrievers; I would be interested in hearing from SPDS users who desire these features.

- ca_certs (string) — advanced option to perform validation of the server's SSL certificate. Specify the path to a PEM-formatted list of 1 or more valid and trusted root certification authority (CA) certificates. Note: this option is only available with Python 2.6 or higher.
  To find out which root CA is used to sign the chain of certificates for a given server, you can run

      openssl s_client -showcerts -connect HOST:PORT < /dev/null 2>/dev/null \
        | grep '^[[:space:]]*i:' | tail -n 1

  If the server's certificate cannot be validated based upon the supplied trusted root certificates, getmail will abort the connection.
  Root certificates are not supplied with getmail; your OS probably installs a set by default for use by the system, or you may wish to use a specific set of trusted root certificates provided by your employer or a trusted third party. Common locations for OS-supplied SSL root certification authority certificates include:
  - Linux (Debian, Ubuntu, Arch, SuSE):

        /etc/ssl/certs/

  - Linux (RedHat, Fedora, CentOS):

        /etc/pki/tls/certs/

  - FreeBSD:

        /usr/local/share/certs/

  - OpenBSD:

        /etc/ssl/

  - OSX:

        /System/Library/OpenSSL/certs/

  - Windows: ask Microsoft
- ssl_ciphers (string) — advanced option to control which SSL cipher algorithms will be allowed to proceed. See the Open SSL documentation for details. If the specified setting results in no possible ciphers available, getmail will abort the connection. Note: this option is only available with Python 2.7 or higher.
- ssl_version (string) — advanced option to control which SSL version getmail tries to use to connect to the server; the default is "sslv23". Another useful value is probably "sslv3". The available option values are taken from the Python ssl module. Note: this option is only available with Python 2.6 or higher.
- ssl_fingerprints (tuple of quoted strings) — advanced option to notice when the server's SSL certificate changes. Supply a list of one or more SHA256 certificate fingerprints, and getmail will confirm whether the server's certificate fingerprint is in the list of allowed fingerprints; if it is not, getmail will abort the connection. Getmail will log the fingerprint of the server's certificate if you supply the --fingerprint commandline option. Note: this option is only available with Python 2.6 or higher.

#### SimplePOP3Retriever

The SimplePOP3Retriever class takes the common retriever parameters above, plus the following optional parameters:

- use_apop (boolean) — if set to True, getmail will use APOP-style authentication to log in to the server instead of normal USER/PASS authentication. This is not supported by many POP3 servers. Note that APOP adds much less security than might be supposed; weaknesses in its hashing algorithm mean that an attacker can recover the first three characters of the password after snooping on only a few hundred authentications between a client and server — see http://www.securityfocus.com/archive/1/464477/30/0/threaded for details. The default is False.
- timeout (integer) — how long (in seconds) to wait for socket operations to complete before considering them failed. If not specified, the default is 180 seconds. You may need to increase this value in particularly poor networking conditions.
- delete_dup_msgids (boolean) — if set to True, and the POP3 server identifies multiple messages as having the same "unique" identifier, all but the first will be deleted without retrieving them.

#### BrokenUIDLPOP3Retriever

This retriever class is intended only for use with broken POP3 servers that either do not implement the UIDL command, or which do not properly assign unique identifiers to messages (preventing getmail from determining which messages it has seen before). It will identify every message in the mailbox as a new message, and therefore if you use this retriever class and opt not to delete messages after retrieval, it will retrieve those messages again the next time getmail is run. Use this retriever class only if your mailbox is hosted on such a broken POP3 server, and the server does not provide another means of getmail accessing it (i.e., IMAP).

The BrokenUIDLPOP3Retriever class takes the common retriever parameters above, plus the following optional parameters:

- use_apop (boolean) — see SimplePOP3Retriever for definition.
- timeout (integer) — see SimplePOP3Retriever for definition.

#### SimpleIMAPRetriever

The SimpleIMAPRetriever class takes the common retriever parameters above, plus the following optional parameters:

- timeout (integer) — see SimplePOP3Retriever for definition.

#### SimplePOP3SSLRetriever

The SimplePOP3SSLRetriever class takes the common retriever parameters above, plus the following optional parameters:

- use_apop (boolean) — see SimplePOP3Retriever for definition.
- delete_dup_msgids (boolean) — see SimplePOP3Retriever for definition.
- ca_certs (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_ciphers (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_version (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_fingerprints (tuple of quoted strings) — see SSL Certificate Validation and Server Parameters for definition

#### BrokenUIDLPOP3SSLRetriever

The BrokenUIDLPOP3SSLRetriever class takes the common retriever parameters above, plus the following optional parameters:

- use_apop (boolean) — see SimplePOP3Retriever for definition.
- keyfile (string) — see SSL Client Parameters for definition.
- certfile (string) — see SSL Client Parameters for definition.
- ca_certs (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_ciphers (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_version (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_fingerprints (tuple of quoted strings) — see SSL Certificate Validation and Server Parameters for definition

#### SimpleIMAPSSLRetriever

The SimpleIMAPSSLRetriever class takes the common retriever parameters above, plus the following optional parameters:

- mailboxes (tuple of quoted strings) — see common retriever parameters for definition.
- move_on_delete (string) — see SimpleIMAPRetriever for definition.
- keyfile (string) — see SSL Client Parameters for definition.
- certfile (string) — see SSL Client Parameters for definition.
- ca_certs (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_ciphers (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_version (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_fingerprints (tuple of quoted strings) — see SSL Certificate Validation and Server Parameters for definition

#### MultidropPOP3Retriever

The MultidropPOP3Retriever class takes the common retriever parameters above, plus the following required parameter:

- envelope_recipient (string) — the name and position of the header field which records the envelope recipient address. This is set to a value of the form field_name : field_position . The first (topmost) Delivered-To: header field would be specified as:

      envelope_recipient = delivered-to:1

The MultidropPOP3Retriever also takes the following optional parameters:

- use_apop (boolean) — see SimplePOP3Retriever for definition.
- timeout (integer) — see SimplePOP3Retriever for definition.

#### MultidropPOP3SSLRetriever

The MultidropPOP3SSLRetriever class takes the common retriever parameters above, plus the following required parameter:

- envelope_recipient (string) — see MultidropPOP3Retriever for definition.

The MultidropPOP3SSLRetriever class alo takes the following optional parameters:

- use_apop (boolean) — see SimplePOP3Retriever for definition.
- keyfile (string) — see SSL Client Parameters for definition.
- certfile (string) — see SSL Client Parameters for definition.
- ca_certs (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_ciphers (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_version (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_fingerprints (tuple of quoted strings) — see SSL Certificate Validation and Server Parameters for definition

#### MultidropSDPSRetriever

The MultidropSDPSRetriever class takes the common retriever parameters above, plus the following optional parameters:

- timeout (integer) — see SimplePOP3Retriever for definition.

#### MultidropIMAPRetriever

The MultidropIMAPRetriever class takes the common retriever parameters above, plus the following required parameter:

- envelope_recipient (string) — see MultidropPOP3Retriever for definition.

The MultidropIMAPRetriever class also takes the following optional parameters:

- timeout (integer) — see SimplePOP3Retriever for definition.
- mailboxes (tuple of quoted strings) — see common retriever parameters for definition.
- move_on_delete (string) — see SimpleIMAPRetriever for definition.

#### MultidropIMAPSSLRetriever

The MultidropIMAPSSLRetriever class takes the common retriever parameters above, plus the following required parameter:

- envelope_recipient (string) — see MultidropPOP3Retriever for definition.

The MultidropIMAPSSLRetriever class also takes following optional parameters:

- mailboxes (tuple of quoted strings) — see common retriever parameters for definition.
- move_on_delete (string) — see SimpleIMAPRetriever for definition.
- keyfile (string) — see SSL Client Parameters for definition.
- certfile (string) — see SSL Client Parameters for definition.
- ca_certs (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_ciphers (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_version (string) — see SSL Certificate Validation and Server Parameters for definition
- ssl_fingerprints (tuple of quoted strings) — see SSL Certificate Validation and Server Parameters for definition

### Retriever examples

A typical POP3 mail account (the basic kind of mailbox provided by most internet service providers (ISPs)) would use a retriever configuration like this:

    [retriever]
    type = SimplePOP3Retriever
    server = popmail.isp.example.net
    username = account_name
    password = my_mail_password

If your ISP provides POP3 access on a non-standard port number, you would need to include the port parameter:

    [retriever]
    type = SimplePOP3Retriever
    server = popmail.isp.example.net
    port = 8110
    username = account_name
    password = my_mail_password

If your ISP provides POP3-over-SSL and you wanted to use that, your retriever configuration might look like this:

    [retriever]
    type = SimplePOP3SSLRetriever
    server = popmail.isp.example.net
    username = account_name
    password = my_mail_password

If you have an IMAP mail account and want to retrieve messages from several mail folders under that account, and you want to move messages to a special folder when deleting them, you would use a retriever configuration like this:

    [retriever]
    type = SimpleIMAPRetriever
    server = imapmail.isp.example.net
    username = account_name
    password = my_mail_password
    mailboxes = ("INBOX", "lists.unix", "lists.getmail")
    move_on_delete = mail.deleted

If you are retrieving your company's mail from a domain POP3 mailbox for delivery to multiple local users, you might use a retriever configuration like this:

    [retriever]
    type = MultidropPOP3Retriever
    server = imapmail.isp.example.net
    username = account_name
    password = company_maildrop_password
    envelope_recipient = delivered-to:1

### Creating the [destination] section

The destination section of the rc file tells getmail what to do with retrieved messages. Begin with the section header line as follows:

    [destination]

Then, include a type string parameter to tell getmail what type of mail destination this is. The possible values are:

- Maildir — deliver all messages to a local qmail-style maildir
- Mboxrd — deliver all messages to a local mboxrd-format mbox file with fcntl-type locking.
- MDA_external — use an external message delivery agent (MDA) to deliver messages. Typical MDAs include maildrop, procmail, and others.
- MultiDestination — unconditionally deliver messages to multiple destinations (maildirs, mbox files, external MDAs, or other destinations).
- MultiSorter — sort messages according to the envelope recipient (requires a domain mailbox retriever) and deliver to a variety of maildirs, mbox files, external MDAs, or other destinations based on regular expressions matching the recipient address of each message. Messages not matching any of the regular expressions are delivered to a default "postmaster" destination.
- MultiGuesser — sort messages according to getmail's best guess at what the envelope recipient of the message might have been, and deliver to a variety of maildirs, mbox files, external MDAs, or other destinations based on regular expressions matching those addresses. Messages not matching any of the regular expressions are delivered to a default "postmaster" destination.
- MDA_qmaillocal — use qmail-local to deliver messages according to instructions in a .qmail file.

#### Maildir

The Maildir destination delivers to a qmail-style maildir. The maildir must already exist, and must contain all of the subdirectories required by the maildir format. getmail will not create the maildir if it does not exist. If you're not familiar with the maildir format, the requirements in a nutshell are: it must be a directory containing three writable subdirectories cur, new, and tmp, and they must all reside on the same filesystem.

The Maildir destination takes one required parameter:

- path (string) — the path to the maildir, ending in slash (/). This value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}. You might want to deliver messages to a maildir named Maildir in your home directory; you could do this with a configuration like this:

      [destination]
      type = Maildir
      path = ~/Maildir/

The Maildir destination also takes two optional parameters:

- user (string) — on Unix-like systems, if supplied, getmail will change the effective UID to that of the named user before delivering messages to the maildir. Note that this typically requires root privileges. getmail will not deliver to maildirs as root, so this "optional" parameter is required in that situation.
- filemode (string) — if supplied, getmail will cause the delivered message files in the maildir to have at most these permissions (given in standard Unix octal notation). Note that the current umask is masked out of the given value at file creation time. The default value, which should be appropriate for most users, is "0600".

#### Mboxrd

The Mboxrd destination delivers to an mboxrd-format mbox file with either fcntl-type (lockf) or flock-type file locking. The file must already exist and appear to be a valid mboxrd file before getmail will try to deliver to it — getmail will not create the file if it does not exist. If you want to create a new mboxrd file for getmail to use, simply create a completely empty (0-byte) file.

You must ensure that all other programs accessing any the mbox file expect mboxrd-format mbox files and the same type of file locking that you configure getmail to use; failure to do so can cause mbox corruption. If you do not know what type of file locking your system expects, ask your system administrator. If you are the system administrator and don't know what type of file locking your system expects, do not use Mboxrd files; use Maildirs instead. Note that delivering to mbox files over NFS can be unreliable and should be avoided; this is the case with any MDA.

The Mboxrd destination takes one required parameter:

- path (string) — the path to the mbox file. This value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}. You might want to deliver messages to an mbox file named inbox in your home directory; you could do this with a configuration like this:

      [destination]
      type = Mboxrd
      path = ~/inbox

The Mboxrd destination also takes two optional parameters:

- user (string) — on Unix-like systems, if supplied, getmail will change the effective UID to that of the named user before delivering messages to the mboxrd file. Note that this typically requires root privileges. getmail will not deliver to mbox files as root, so this "optional" parameter is required in that situation.
- locktype (string) — which type of file locking to use; may be "lockf" (for fcntl locking) or "flock". The default in getmail 4.7.0 and later is lockf.

#### MDA_external

MDA_external delivers messages by running an external program (known as a message delivery agent, or MDA) and feeding it the message on its standard input. Some typical MDAs include maildrop and procmail.

The MDA_external destination takes one required parameter:

- path (string) — the path to the command to run. This value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}.

The MDA_external destination also takes several optional parameters:

- arguments (tuple of quoted strings) — arguments to be supplied to the command. The following substrings will be substituted with the equivalent values from the message:
  - %(sender) — envelope return-path address
  If the message is retrieved with a multidrop retriever class, the message recipient (and parts of it) are also available with the following replacement substrings:
  - %(recipient) — envelope recipient address
  - %(local) — local-part of the envelope recipient address
  - %(domain) — domain-part of the envelope recipient address
  - %(mailbox) — the IMAP mailbox name the message was retrieved from; for POP, this will be empty
  The default value of the arguments parameter is (), so no arguments are supplied to the command.
- unixfrom (boolean) — whether to include a Unix-style mbox From_ line at the beginning of the message supplied to the command. Defaults to false. Some MDAs expect such a line to be present and will fail to operate if it is missing.
- user (string) — if supplied, getmail will change the effective UID to that of the named user. Note that this typically requires root privileges.
- group (string) — if supplied, getmail will change the effective GID to that of the named group. Note that this typically requires root privileges.
- allow_root_commands (boolean) — if set, getmail will run external commands even if it is currently running with root privileges. The default is false, which causes getmail to raise an exception if it is asked to run an external command as root. Note that setting this option has serious security implications. Don't use it if you don't know what you're doing. I strongly recommend against running external processes as root.
- ignore_stderr (boolean) — if set, getmail will not consider it an error if the program writes to stderr. The default is false, which causes getmail to consider the delivery failed and leave the message on the server, proceeding to the next message. This prevents loss of mail if the MDA writes to stderr but fails to exit nonzero when it encounters an error. Note that setting this option has serious implications; some MDAs can fail to deliver a message but still exit 0, which can cause loss of mail if this option is set. Only change this setting if you are confident your MDA always exits nonzero on error.

A basic invocation of an external MDA might look like this:

    [destination]
    type = MDA_external
    path = /path/to/mymda
    arguments = ("--log-errors", )

Something more complex might look like this:

    [destination]
    type = MDA_external
    path = /path/to/mymda
    # Switch to fred's UID and the mail group GID before delivering his mail
    user = fred
    group = mail
    arguments = ("--strip-forbidden-attachments", "--recipient=%(recipient)")

#### MultiDestination

MultiDestination doesn't do any message deliveries itself; instead, it lets you specify a list of one or more other destinations which it will pass each message to. You can use this to deliver each message to several different destinations.

The MultiDestination destination takes one required parameter:

- destinations (tuple of quoted strings) — the destinations which the messages will be passed to. A destination is a string that refers to another configuration file section by name (shortcuts for maildirs and mboxrd files are also provided; see below), like this:

      destinations = ('[other-destination-1]', '[other-destination-2]')

      [other-destination-1]
      type = Mboxrd
      path = /var/spool/mail/alice
      user = alice

      [other-destination-2]
      type = Maildir
      path = /home/joe/Maildir/
      user = joe

  Because Maildir and Mboxrd destinations are common, you can specify them directly as a shortcut if they do not require a user parameter. If the string (after expansion; see below) starts with a dot or slash and ends with a slash, it specifies the path of a Maildir destination, while if it starts with a dot or a slash and does not end with a slash, it specifies the path of a Mboxrd destination.

  For instance, you can deliver mail to two maildirs with the following:

      destinations = ('~/Mail/inbox/', '~/Mail/archive/current/')

  Each destination string is first expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}.

Some examples:

- To deliver to a maildir named Maildir in the home directory of user jeff, when getmail is run as that user:

      [destination]
      type = MultiDestination
      destinations = ("~jeff/Maildir/", )

- To deliver to an mboxrd file:

      [destination]
      type = MultiDestination
      destinations = ("/var/spool/mail/alice", )

- To deliver with an external MDA:

      [destination]
      type = MultiDestination
      destinations = ("[procmail-as-bob]", )

      [procmail-as-bob]
      type = MDA_external
      path = /path/to/procmail
      arguments = ('~bob/.procmailrc', '-f', '%(sender)')
      user = bob

Of course, the whole point of MultiDestination is to allow you to specify multiple destinations, like this:

    [destination]
    type = MultiDestination
    destinations = (
        "~jeff/Mail/inbox",
        "[procmail-as-jeff]",
        "/var/mail-archive/incoming"
        )

    [procmail-as-jeff]
    type = MDA_external
    path = /path/to/procmail
    arguments = ('~jeff/.procmailrc', '-f', '%(sender)')
    user = jeff

#### MultiSorter

MultiSorter compares the envelope recipient address of messages against a list of user-supplied regular expressions and delivers the message to the destination (maildir, mboxrd file, or other) associated with any matching patterns. A message can match multiple patterns and therefore be delivered to multiple matching destinations. Any message which matches none of the patterns is delivered to a default destination for the postmaster.

Because MultiSorter requires the envelope recipient to operate, it must be used with a domain mailbox retriever. If you instead want to do some basic message sorting based on getmail's best guess as to the envelope recipient of the message, see the MultiGuesser destination class below.

The MultiSorter destination takes one required parameter:

- default (string) — the destination for messages which aren't matched by any of the "locals" regular expressions. The destination can be a maildir, mboxrd file, or other destination. See MultiDestination for an explanation of how the type of destination is interpreted from this value.

The MultiSorter destination also takes one optional parameter:

- locals (tuple of 2-tuples) — zero or more regular expression – destination pairs. Messages will be delivered to each destination for which the envelope recipient matches the given regular expression. The regular expression and destination are supplied as two quoted strings in a tuple; locals is then a tuple of such pairs of strings. Destinations are specified in the same manner as with the "default" parameter, above.

Important note: if your regular expression contains backslashes (by themselves, or as part of an escaped character or symbol like \n or \W ), you need to tell the parser that this expression must be parsed "raw" by prepending the string with an "r":

    locals = (
        (r'jeff\?\?\?@.*', '[jeff]'),
        ('alice@', '[alice]')
        )

    locals = (
        ('jeff@.*', '[jeff]'),
        (r'alice\D+@', '[alice]')
        )

Note that if you don't understand regular expressions, you don't need to worry about it. In general, an email address is a regular expression that matches itself. The only significant times this isn't the case is when the address contains odd punctuation characters like ^, $, \, or [. Handy hints:

- the regular expression . (dot) matches anything
- matches can occur anywhere in the address. If you want to only match at the beginning, start your expression with the ^ character. If you only want to match the whole address, also end your expression with a dollar sign $.

Using regular expressions:

- The regular expression joe@example.org matches the addresses joe@example.org, joe@example.org.net, and heyjoe@example.org.
- The regular expression ^jeff@ matches the addresses jeff@example.org and jeff@example.net, but not otherjeff@example.org.
- The regular expression sam matches the addresses sam@example.org, samantha@example.org, asam@example.org, and chris@isam.example.net.

Some examples:

- - Deliver mail matching jeff@example.net to ~jeff/Maildir/
  - Deliver mail matching alice@anything to ~alice/inbox
  - Deliver all other mail to ~bob/Maildir/

      [destination]
      type = MultiSorter
      default = [bob-default]
      locals = (
          ('jeff@example.net', '[jeff]'),
          ('alice@', '[alice]')
          )

      [jeff]
      type = Maildir
      path = ~jeff/Maildir/
      user = jeff

      [alice]
      type = Mboxrd
      path = ~alice/inbox
      user = alice

      [bob-default]
      type = Maildir
      path = ~bob/Maildir/
      user = bob

- - Deliver mail for jeff, bob, and alice to maildirs in their home directories
  - Deliver copies of all messages to samantha's mail archive
  - Deliver copies of all messages to a program that logs certain information. This program should run as the user log, and command arguments should tell it to record the info to /var/log/mail/info

      [destination]
      type = MultiSorter
      default = doesn't matter, this won't be used, as locals will always match
      locals = (
          ('^jeff@', '[jeff]'),
          ('^bob@', '[bob]'),
          ('^alice@', '[alice]'),
          ('.', '[copies]'),
          ('.', '[info]')
          )

      [alice]
      type = Maildir
      path = ~alice/Maildir/
      user = alice

      [bob]
      type = Maildir
      path = ~bob/Maildir/
      user = bob

      [jeff]
      type = Maildir
      path = ~jeff/Maildir/
      user = jeff

      [copies]
      type = Maildir
      path = ~samantha/Mail/archive/copies/
      user = samantha

      [info]
      type = MDA_external
      path = /path/to/infologger
      arguments = ('--log=/var/log/mail/info', '--sender=%(sender)', '--recipient=%(recipient))
      user = log

#### MultiGuesser

MultiGuesser tries to guess what the envelope recipient address of the message might have been, by comparing addresses found in the message header against a list of user-supplied regular expressions, and delivers the message to the destination (maildir, mboxrd file, or other) associated with any matching patterns. A message can match multiple patterns and therefore be delivered to multiple matching destinations. Any message which matches none of the patterns is delivered to a default destination for the postmaster. In this fashion, you can do basic mail filtering and sorting with getmail without using an external filtering message delivery agent (MDA) (such as maildrop or procmail), if and only if the message recipient is the criteria you want to filter on.

If you want to filter based on arbitrary message critera, like "What address is in the To: header field?" or "Who is the message from?", then use the filtering MDA of your choice, called from a getmail MDA_external destination.

MultiGuesser is similar to MultiSorter, except that it does not operate on the true envelope recipient address, and therefore does not require a domain mailbox retriever. Because it is "guessing" at the intended recipient of the message based on the contents of the message header, it is fallible — for instance, the address of a recipient of a mailing list message may not appear in the header of the message at all. If your locals regular expression patterns are only looking for that address, MultiGuesser will then have to deliver it to the destination specified as the default recipient.

This functionality is very similar to the guessing functionality of getmail version 2, which was removed in version 3. MultiGuesser extracts a list of addresses from the message header like this:

1. it looks for addresses in any Delivered-To: header fields.
2. if no addresses have been found, it looks for addresses in any Envelope-To: header fields.
3. if no addresses have been found, it looks for addresses in any X-Envelope-To: header fields.
4. if no addresses have been found, it looks for addresses in any Apparently-To: header fields.
5. if no addresses have been found, it looks for addresses in any Resent-to: or Resent-cc: header fields (or Resent-bcc:, which shouldn't be present).
6. if no addresses have been found, it looks for addresses in any To: or cc: header fields (or bcc:, which shouldn't be present).

The MultiGuesser destination takes one required parameter:

- default (string) — see MultiSorter for definition.

The MultiGuesser destination also takes one optional parameter:

- locals (tuple of 2-tuples) — see MultiSorter for definition.

Examples:

If you have a simple POP3 account (i.e. it's not a multidrop mailbox) and you want to deliver your personal mail to your regular maildir, but deliver mail from a couple of mailing lists (identified by the list address appearing in the message header) to separate maildirs, you could use a MultiGuesser configuration like this:

    [destination]
    type = MultiGuesser
    default = ~/Maildir/
    locals = (
        ("list-address-1@list-domain-1", "~/Mail/mailing-lists/list-1/"),
        ("list-address-2@list-domain-2", "~/Mail/mailing-lists/list-2/"),
        )

See MultiSorter above for other examples of getmail rc usage; the only difference is the type parameter specifying the MultiGuesser destination.

#### MDA_qmaillocal

MDA_qmaillocal delivers messages by running the qmail-local program as an external MDA. qmail-local uses .qmail files to tell it what to do with messages. If you're not already familiar with qmail, you don't need to use this destination class.

The MDA_qmaillocal destination takes several optional parameters:

- qmaillocal (string) — path to the qmail-local program. The default value is /var/qmail/bin/qmail-local.
- user (string) — supplied to qmail-local, and also tells getmail to change the current effective UID to that of the named user before running qmail-local. Note that this typically requires root privileges. The default value is the account name of the current effective UID.
- group (string) — if supplied, getmail will change the effective GID to that of the named group before running qmail-local. Note that this typically requires root privileges.
- homedir (string) — supplied to qmail-local. The default value is the home directory of the account with the current effective UID.
- localdomain (string) — supplied to qmail-local as its domain argument. The default value is the fully-qualified domain name of the local host.
- defaultdelivery (string) — supplied to qmail-local as its defaultdelivery argument. The default value is ./Maildir/.
- conf-break (string) — supplied to qmail-local as its dash argument. The default value is -.
- localpart_translate (2-tuple of quoted strings) — if supplied, the recipient address of the message (which is used to construct the local argument (among others) to qmail-local) will have any leading instance of the first string replaced with the second string. This can be used to remap recipient addresses, trim extraneous prefixes (such as the qmail virtualdomain prepend value), or perform other tasks. The default value is ('', '') (i.e., no translation).
- strip_delivered_to (boolean) — if set, Delivered-To: header fields will be removed from the message before handing it to qmail-local. This may be necessary to prevent qmail-local falsely detecting a looping message if (for instance) the system retrieving messages otherwise believes it has the same domain name as the retrieval server. Inappropriate use of this option may cause message loops. The default value is False.
- allow_root_commands (boolean) — if set, getmail will run qmail-local even if it is currently running with root privileges. The default is false, which causes getmail to raise an exception if it is asked to run an external command as root. Note that setting this option has serious security implications. Don't use it if you don't know what you're doing. I strongly recommend against running external processes as root.

A basic invocation of qmail-local might look like this:

    [destination]
    type = MDA_qmaillocal
    user = joyce

Something more complex might look like this:

    [destination]
    type = MDA_qmaillocal
    user = joyce
    # The mail domain isn't the normal FQDN of the server running getmail
    localdomain = host.example.net
    # Trim the server's virtualdomain prepend value from message recipient before
    # sending it to qmail-local
    localpart_translate = ('mailhostaccount-', '')

### Creating the [options] section

The optional options section of the rc file can be used to alter getmail's default behaviour. The parameters supported in this section are as follows:

- verbose (integer) — controls getmail's verbosity. If set to 2, getmail prints messages about each of its actions. If set to 1, it prints messages about retrieving and deleting messages (only). If set to 0, getmail will only print warnings and errors. Default: 1.
- read_all (boolean) — if set, getmail retrieves all available messages. If unset, getmail only retrieves messages it has not seen before. Default: True.
- delete (boolean) — if set, getmail will delete messages after retrieving and successfully delivering them. If unset, getmail will leave messages on the server after retrieving them. Default: False.
- delete_after (integer) — if set, getmail will delete messages this number of days after first seeing them, if they have been retrieved and delivered. This, in effect, leaves messages on the server for a configurable number of days after retrieving them. Note that the delete parameter has higher priority; if both are set, the messages will be deleted immediately. Default: 0, which means not to enable this feature.
- delete_bigger_than (integer) — if set, getmail will delete messages larger than this number of bytes after retrieving them, even if the delete and delete_after options are disabled. The purpose of this feature is to allow deleting only large messages, to help keep a mailbox under quota. Has no effect if delete is set, as that will unconditionally remove messages. If delete_after is also set, the message will be deleted immediately after retrieval if it is over this size, and otherwise will be deleted according to the setting of delete_after. Default: 0, which means not to enable this feature.
- max_bytes_per_session (integer) — if set, getmail will retrieve messages totalling up to this number of bytes before closing the session with the server. This can be useful if you do not want large messages causing large bursts of network traffic. Default: 0, which means not to enable this feature. Note that message sizes reported by the server are used, and therefore may vary slightly from the actual size on disk after message retrieval.
- max_message_size (integer) — if set, getmail will not retrieve messages larger than this number of bytes. Default: 0, which means not to enable this feature.
- max_messages_per_session (integer) — if set, getmail will process a maximum of this number of messages before closing the session with the server. This can be useful if your network or the server is particuarly unreliable. Default: 0, which means not to enable this feature.
- delivered_to (boolean) — if set, getmail adds a Delivered-To: header field to the message. If unset, it will not do so. Default: True. Note that this field will contain the envelope recipient of the message if the retriever in use is a multidrop retriever; otherwise it will contain the string "unknown".
- received (boolean) — if set, getmail adds a Received: header field to the message. If unset, it will not do so. Default: True.
- message_log (string) — if set, getmail will record a log of its actions to the named file. The value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}. Default: '' (the empty string), which means not to enable this feature.
- message_log_syslog (boolean) — if set, getmail will record a log of its actions using the system logger. Note that syslog is inherently unreliable and can lose log messages. Default: False.
- message_log_verbose (boolean) — if set, getmail will log to the message log file (or syslog) information about messages not retrieved and the reason for not retrieving them, as well as starting and ending information lines. By default, it will log only about messages actually retrieved, and about error conditions. Note that this has no effect if neither message_log nor message_log_syslog is in use. Default: False.

Most users will want to either enable the delete option (to delete mail after retrieving it), or disable the read_all option (to only retrieve previously-unread mail).

The verbose, read_all, and delete parameters can be overridden at run time with commandline options.

#### [options] example

To configure getmail to operate quietly, to retrieve only new mail, to delete messages after retrieving them, and to log its actions to a file, you could provide the following in your getmail rc file(s):

    [options]
    verbose = 0
    read_all = false
    delete = true
    message_log = ~/.getmail/log

### Creating the [filter-something] sections

The filter-something section(s) of the rc file (which are not required) tell getmail to process messages in some way after retrieving them, but before delivering them to your destinations. Filters can tell getmail to drop a message (i.e. not deliver it at all), add information to the message header (i.e. for a spam- classification system or similar), or modify message content (like an antivirus system stripping suspected MIME parts from messages).

You can specify any number of filters; provide a separate rc file section for each, naming each of them filter-something. They will be run in collated order, so it's likely simplest to name them like this:

- [filter-1]
- [filter-2]
- [filter-3]

Begin with the section header line as follows:

    [filter-something]

Then, include a type string parameter to tell getmail what type of filter. The possible values are:

- Filter_classifier — run the message through an external program, and insert the output of the program into X-getmail-filter-classifier: header fields in the message. Messages can be dropped by having the filter return specific exit codes.
- Filter_external — supply the message to an external program, which can then modify the message in any fashion. The program must print the modified message to stdout. getmail reads the modified message from the program in this fasion before proceeding to the next filter or destination. Messages can be dropped by having the filter return specific exit codes.
- Filter_TMDA — run the message through the tmda-filter program for use with the Tagged Message Delivery Agent (TMDA) package. If tmda-filter returns 0, the message will be passed to the next filter (or destination). If it returns 99, the message will be dropped, and TMDA is responsible for sending a challenge message, queuing the original, etc., as with normal TMDA operation in a .qmail, .courier, or .forward file.

By default, if a filter writes anything to stderr, getmail will consider the delivery to have encountered an error. getmail will leave the message on the server and proceed to the next message. You must configure any filter you use not to emit messages to stderr except on errors — please see the documentation for your filter program for details. Optionally, if you know your filter can emit warnings on stderr under non-error conditions, you can set the ignore_stderr option.

#### Filter_classifier

Filter_classifier runs the message through an external program, placing the output of that program into X-getmail-filter-classifier: header fields. It can also cause messages to be dropped by exiting with a return code listed in the exitcodes_drop parameter.

Filter_classifier has one required parameter:

- path (string) — the path to the command to run. This value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}.

In addition, Filter_classifier takes the following optional parameters:

- arguments (tuple of quoted strings) — arguments to be supplied to the command. The following substrings will be substituted with the equivalent values from the message:
  - %(sender) — envelope return-path address
  If the message is retrieved with a multidrop retriever class, the message recipient (and parts of it) are also available with the following replacement substrings:
  - %(recipient) — envelope recipient address
  - %(local) — local-part of the envelope recipient address
  - %(domain) — domain-part of the envelope recipient address
  The default value of the arguments parameter is (), so no arguments are supplied to the command.
- unixfrom (boolean) — whether to include a Unix-style mbox From_ line at the beginning of the message supplied to the command. Default: False.
- user (string) — if supplied, getmail will change the effective UID to that of the named user. Note that this typically requires root privileges.
- group (string) — if supplied, getmail will change the effective GID to that of the named group. Note that this typically requires root privileges.
- allow_root_commands (boolean) — if set, getmail will run external commands even if it is currently running with root privileges. The default is false, which causes getmail to raise an exception if it is asked to run an external command as root. Note that setting this option has serious security implications. Don't use it if you don't know what you're doing. I strongly recommend against running external processes as root.
- ignore_stderr (boolean) — if set, getmail will not consider it an error if the filter writes to stderr. The default is false, which causes getmail to consider the delivery failed and leave the message on the server, proceeding to the next message. This prevents loss of mail if the filter writes to stderr but fails to exit nonzero when it encounters an error. Note that setting this option has serious implications; some poorly-written programs commonly used as mail filters can can mangle or drop mail but still exit 0, their only clue to failure being warnings emitted on stderr. Only change this setting if you are confident your filter always exits nonzero on error.
- exitcodes_drop (tuple of integers) — if the filter returns an exit code in this list, the message will be dropped. The default is (99, 100).
- exitcodes_keep (tuple of integers) — if the filter returns an exit code other than those in exitcodes_drop and exitcodes_keep, getmail assumes the filter encountered an error. getmail will then not proceed, so that the message is not lost. The default is (0, ).

#### Filter_external

Filter_external runs the message through an external program, and replaces the message with the output of that program, allowing the filter to make arbitrary changes to messages. It can also cause messages to be dropped by exiting with a return code listed in the exitcodes_drop parameter.

Filter_external has one required parameter:

- path (string) — see Filter_classifier for definition.

In addition, Filter_external takes the following optional parameters:

- arguments (tuple of quoted strings) — see Filter_classifier for definition.
- unixfrom (boolean) — see Filter_classifier for definition.
- user (string) — see Filter_classifier for definition.
- group (string) — see Filter_classifier for definition.
- allow_root_commands (boolean) — see Filter_classifier for definition.
- ignore_stderr (boolean) — see Filter_classifier for definition.
- exitcodes_drop (tuple of integers) — see Filter_classifier for definition.
- exitcodes_keep (tuple of integers) — see Filter_classifier for definition.

#### Filter_TMDA

Filter_external runs the message through the external program tmda-filter, allowing the use of the Tagged Message Delivery Agent (TMDA) package. As TMDA relies on the message envelope, this filter requires the use of a multidrop retriever class to function. It sets the three environment variables SENDER, RECIPIENT, and EXT prior to running tmda-filter.

I've tested this filter, and it Works For Me™, but I'm not a regular TMDA user. I would appreciate any feedback about its use from TMDA users.

Filter_TMDA has no required parameters. It has the following optional parameters:

- path (string) — the path to the tmda-filter binary. Default: /usr/local/bin/tmda-filter. This value will be expanded for leading ~ or ~USER and environment variables in the form $VARNAME or ${VARNAME}.
- user (string) — see Filter_classifier for definition.
- group (string) — see Filter_classifier for definition.
- allow_root_commands (boolean) — see Filter_classifier for definition.
- ignore_stderr (boolean) — see Filter_classifier for definition.
- conf-break (string) — this value will be used to split the local-part of the envelope recipient address to determine the value of the EXT environment variable. For example, if the envelope sender address is sender-something@host.example.org, and the envelope recipient address is user-ext-ext2@host.example.net, and conf-break is set to -, getmail will set the environment variables SENDER to "sender-something@host.example.org", RECIPIENT to "user-ext-ext2@host.example.net", and EXT to "ext-ext2". Default: "-".

#### [filter-something] examples

You might filter spam messages in your MUA based on information added to the message header by a spam-classification program. You could have that information added to the message header with a filter configuration like this:

    [filter-3]
    type = Filter_classifier
    path = /path/to/my-classifier
    arguments = ('--message-from-stdin', '--report-to-stdout')
    user = nobody

You might use a program to prevent users from accidentally destroying their data by stripping suspected attachments from messages. You could have that information added to the message header with a filter configuration like this:

    [filter-3]
    type = Filter_external
    path = /path/to/my-mime-filter
    arguments = ('--message-from-stdin', '--remove-all-but-attachment-types=text/plain,text/rfc822')
    user = nobody

You might use TMDA to challenge messages from unknown senders. If the default parameters are fine for your configuration, this is as simple as:

    [filter-3]
    type = Filter_TMDA

### getmail rc file examples

Several examples of different getmail rc configuration are available in the included file getmailrc-examples.

# Running getmail

To use getmail, simply run the script getmail, which is typically installed in /usr/local/bin/ by default. getmail will read the default getmail rc file (getmailrc) from the default configuration/data directory (~/.getmail/) and begin operating.

You can modify this behaviour by supplying commandline options to getmail.

## Commandline options

getmail understands the following options:

- --version — show getmail's version number and exit
- --help or -h — show a brief usage summary and exit
- --getmaildir=DIR or -gDIR — use DIR for configuration and data files
- --rcfile=FILE or -rFILE — read getmail rc file FILE instead of the default. The file path is assumed to be relative to the getmaildir directory unless this value starts with a slash (/). This option can be given multiple times to have getmail retrieve mail from multiple accounts.
- --dump — read rc files, dump configuration, and exit (debugging)
- --trace — print extended debugging information

If you are using a single getmailrc file with an IMAP server that understands the IDLE extension from RFC 2177, you can use the --idle=MAILBOX option to specify that getmail should wait on the server to notify getmail of new mail in the specified mailbox after getmail is finished retrieving mail.

In addition, the following commandline options can be used to override any values specified in the [options] section of the getmail rc files:

- --verbose or -v — operate more verbosely. Can be given multiple times.
- --quiet or -q — print only warnings or errors while running
- --delete or -d — delete messages after retrieving
- --dont-delete or -l — do not delete messages after retrieving
- --all or -a — retrieve all messages
- --new or -n — retrieve only new (unseen) messages

For instance, if you want to retrieve mail from two different mail accounts, create a getmail rc file for each of them (named, say, getmailrc-account1 and getmailrc-account2) and put them in ~/.getmail/ . Then run getmail as follows:

    $ getmail --rcfile getmailrc-account1 --rcfile getmailrc-account2

If those files were located in a directory other than the default, and you wanted to use that directory for storing the data files as well, you could run getmail as follows:

    $ getmail --getmaildir /path/to/otherdir --rcfile getmailrc-account1 --rcfile getmailrc-account2

## Using getmail as an MDA

getmail includes helper scripts which allow you to use it to deliver mail from other programs to maildirs or mboxrd files.

### Using the getmail_maildir MDA

The getmail_maildir script can be used as an MDA from other programs to deliver mail to maildirs. It reads the mail message from stdin, and delivers it to a maildir path provided as an argument on the commandline. This path must (after expansion by the shell, if applicable) start with a dot or slash and end with a slash.

getmail_maildir uses the contents of the SENDER environment variable to construct a Return-Path: header field and the contents of the RECIPIENT environment variable to construct a Delivered-To: header field at the top of the message.

getmail_maildir also accepts the options --verbose or -v which tell it to print a status message on success. The default is to operate silently unless an error occurs.

#### Example

You could deliver a message to a maildir named Maildir located in your home directory by running the following command with the message on stdin:

    $ getmail_maildir $HOME/Maildir/

### Using the getmail_mbox MDA

The getmail_mbox script can be used as an MDA from other programs to deliver mail to mboxrd-format mbox files. It reads the mail message from stdin, and delivers it to an mbox path provided as an argument on the commandline. This path must (after expansion by the shell, if applicable) start with a dot or slash and not end with a slash.

getmail_maildir uses the contents of the SENDER environment variable to construct a Return-Path: header field and mbox From_ line and the contents of the RECIPIENT environment variable to construct a Delivered-To: header field at the top of the message.

getmail_mbox also accepts the options --verbose or -v which tell it to print a status message on success. The default is to operate silently unless an error occurs.

#### Example

You could deliver a message to an mboxrd-format mbox file named inbox located in a directory named mail in your home directory by running the following command with the message on stdin:

    $ getmail_mbox $HOME/mail/inbox

## Using getmail_fetch to retrieve mail from scripts

getmail includes the getmail_fetch helper script, which allows you to retrieve mail from a POP3 server without the use of a configuration file. It is primarily intended for use in automated or scripted environments, but can be used to retrieve mail normally.

See the getmail_fetch manual page for details on the use of getmail_fetch.