Getmail

Getmail is a small Python script to retrieve emails from IMAP accounts (e.g. gmx.de, gmail.com) and deliver these emails to the Mailcow/Dovecot mailbox. I wrote to Getmail because I couldn't find any other solution with IMAP-IDLE in 2018 mailcow/mailcow-dockerized#1554. Emails are retrieved using IMAP IDLE, so emails are retrieved immediately and not after a fixed interval (as with imapsync from Mailcow). The transfer to Mailcow is done via LMTP interface (simplified SNMP) from Dovecot, so you can also use the sieve rules from Dovecoat (imapsync from Mailcow only allows a fixed folder). The goal of Getmail is to empty the entire INBOX. If the source IMAP account contains emails, you should copy/move them to another folder for testing (e.g. with an email programm or webmail).

Install:

• Clone getmail

  cd /opt
  git clone https://github.com/christianbur/getmail.git
  cd /opt/getmail
  

• Copy the docker-compose.override.yml file to the mailcow-dockerized folder. Please check if there is already a docker-compose.override.yml in the mailcow directory!!

  cp /opt/getmail/mailcow-dockerized_docker-compose.override.yml /opt/mailcow-dockerized/docker-compose.override.yml
  

• Because the docker network "network-getmail" is used independently in mailcow and getmail, the network "network-getmail" must be created externally (i.e. not in the docker-compose.yml). Any other IP range can be used, it should only not be already in use (test: ip show -6 route show, ip show route show).

   docker network create --driver=bridge --ipv6 --subnet=fdcb:9c90:23:11::/64 --gateway=fdcb:9c90:23:11::1 --subnet=172.23.11.0/24 --gateway=172.23.11.1 -o "com.docker.network.bridge.name"="br-getmail" network-getmail
  

• Config file must be customized

   cp /opt/getmail/settings.ini.example  /opt/getmail/settings.ini
   vi /opt/getmail/settings.ini
  

• Start mailcow and getmail.

   cd /opt/getmail
   docker compose build 
   docker compose  up -d
  

• Now check the logs from getmail

  docker compose logs
  

Config

Getmail is configured with the configuration file .getmail/settings.ini. Everything under [DEFAULT] applies to all IMAP accounts. Mostly only imap_hostname:, imap_username:, imap_password: have to be customized. In the source IMAP account only one folder is monitored (default = imap_sync_folder: INBOX), if the junk folder should also be monitored, two accounts must be created.

[INBOX_test_gmx.de]
imap_hostname:     imap.gmx.net
imap_username:     [email protected]
imap_password:     xxx
# INFO: "imap_sync_folder: INBOX" is default

[JUNK_test_gmx.de]
imap_hostname:     imap.gmx.net
imap_username:     [email protected]
imap_password:     xxx
imap_sync_folder:  Junk

Normally retrieved emails are deleted from the source IMAP account (imap_move_enable: False), the goal of the script is to completely empty the monitored folder (e.g. INBOX). It is also possible to move the emails to a folder in the IMAP source account; the emails are then available in both the IMAP source account and the IMAP target account.

imap_move_enable: True
imap_move_folder: getmail
# "getmail" "getmail" is an existing folder in the IMAP source account

With 'lmtp_recipient:' you specify the destination imap account in mailcow.

Sieve filter: In every retrieved email, two header (X-getmail-retrieved-from-mailbox-user, X-getmail-retrieved-from-mailbox-folder) are added, with this information you can filter with sieve (Mailcow: Mail Setup -> Filters -> Add Filter)

Example:

require "fileinto";
require "regex";
require "body";

...
if header :contains ["X-getmail-retrieved-from-mailbox-user"] ["[email protected]", "[email protected]"]
{
    fileinto "INBOX/Getmail_GMX";
}
elsif header :contains ["X-getmail-retrieved-from-mailbox-user"] ["[email protected]", "[email protected]"]
{
    fileinto "INBOX/Getmail_Outlook";
}
else
{
  # The rest goes into INBOX
  # default is "implicit keep", we do it explicitly here
  keep;
}

TZ variable:

The TZ vairable defines the time zone. I have defined the variable in the file /etc/default/locale (reboot may be necessary afterwards)

# cat /etc/default/locale
LANG="en_US.UTF-8"
LANGUAGE="en_US:en"
TZ="Europe/Berlin"

Alternatively, you can replace TZ=${TZ} with TZ="Europe/Berlin" in the docker-compose.yml.

If the TZ variable is not defined, the following error message appears when starting getmail: "WARNING: The TZ variable is not set. Defaulting to a blank string."