docker-dovecot-getmail

docker-dovecot-getmail is a Docker image based on Debian implementing a private email gateway with dovecot and getmail for gathering emails from multiple accounts on a private server (IMAP), but using a public email infrastructure for sending (SMTP).

It is a Docker container realizing a similar architecture to:

• http://joel.porquet.org/wiki/hacking/getmail_dovecot/

+-----------+              +-----------+               +--------------+
| ISP       |              | DOCKER    |               | LAPTOP       |
|           |              |           |           +-->|--------------|
| +-------+ | push/delete  | +-------+ | push/sync |   |  MAIL CLIENT +---+
| | IMAPS +----------------->| IMAPS +<------------+   +--------------+   |
| +-------+ |              | +-------+ |           |   +--------------+   |
| +-------+ |              |           |           |   | ANDROID      |   |
| | SMTP  |<-------+       |           |           +-->|--------------|   |
| +-------+ |      |       |           |               |  MAIL CLIENT +---+
+-----------+      |       +-----------+               +--------------+   |
                   +------------------------------------------------------+

Open source project:

• github: http://github.com/gw0/docker-dovecot-getmail/
• technology: debian, dovecot, getmail
• docker hub: https://hub.docker.com/r/gw000/dovecot-getmail/

Usage

Requirements:

• /home: mounted users directories (Maildir in fs layout, sieve, .getmail)
• /etc/cron.d: mounted crontabs for executing all getmail accounts
• /etc/ssl/private: mounted SSL/TLS certificates (dovecot.crt, dovecot.key)

Prepare your getmailrc account configurations per user (/srv/mail/home/user/.getmail/getmailrc-user@email.invalid):

# ~/.getmail/getmailrc-*: getmailrc email configuration

[retriever]
type = SimpleIMAPSSLRetriever
server = imap.email.invalid
username = user@email.invalid
port = 993
password = password
mailboxes = ("INBOX", "Sent", "Spam")

[destination]
type = MDA_external
path = /usr/lib/dovecot/deliver
arguments = ("-e",)

[options]
read_all = false
delete_after = 30
delivered_to = false
received = true
verbose = 1

If you are using Sieve filters and want a Refilter mailbox to trigger their refiltering, create a refilter configuration per user (/srv/mail/home/user/.getmail/getmailrc-refilter):

# ~/.getmail/getmailrc-*: getmailrc refilter configuration

[retriever]
type = SimpleIMAPRetriever
server = localhost
port = 143
username = user
password = password
mailboxes = ("Refilter",)

[destination]
type = MDA_external
path = /usr/lib/dovecot/deliver
arguments = ("-e",)

[options]
read_all = false
delete = true
delivered_to = false
received = false
verbose = 1

Prepare crontab file (/srv/mail/cron.d/getmail) for periodically checking for new mail for each user and account:

# /etc/cron.d/getmail: system-wide crontab for getmail
SHELL=/bin/sh

# m h dom mon dow user  command
*/20 *  *   *   * user  ACC="user-refilter" && (date; flock -n ~/.getmail/lock-$ACC getmail --rcfile="getmailrc-$ACC" --idle Refilter) >>"/var/log/getmail/$ACC.log" 2>&1
*/20 *  *   *   * user  ACC="user@email.invalid" && (date; flock -n ~/.getmail/lock-$ACC getmail --rcfile="getmailrc-$ACC" --idle INBOX) >>"/var/log/getmail/$ACC.log" 2>&1

Do not forget to place your SSL certificates as /srv/mail/ssl/dovecot.crt and /srv/mail/ssl/dovecot.key. SSL is required!

And finally start it with docker:

$ docker run -d -v /srv/mail/home:/home -v /srv/mail/cron.d:/etc/cron.d -v /srv/mail/ssl:/etc/ssl/private:ro -p 143 -p 993 -p 4190 --name mail gw000/dovecot-getmail

Or use docker-compose (check out docker-compose.example.yml).

Users are created automatically with default password (replaceMeNow) on first start. To reset user passwords (of a running container):

$ docker exec -it mail passwd user

Feedback

If you encounter any bugs or have feature requests, please file them in the issue tracker or even develop it yourself and submit a pull request over GitHub.

License

Copyright © 2016-2021 gw0 [http://gw.tnode.com/] <gw.2021@ena.one>

This library is licensed under the GNU Affero General Public License 3.0+ (AGPL-3.0+). Note that it is mandatory to make all modifications and complete source code of this library publicly available to any user.