mailcow-dockerized-docs/docs/u_e-dovecot-expunge.md

If you want to delete old mails out of the .Junk or .Trash folders or maybe delete all read mails that are older than a certain amount of time you may use dovecot's tool doveadm man doveadm-expunge.

The manual way

That said, let's dive in:

Delete a user's mails inside the junk folder that are read and older than 4 hours

docker-compose exec dovecot-mailcow doveadm expunge -u 'mailbox@example.com' mailbox 'Junk' SEEN not SINCE 4h

Delete all user's mails in the junk folder that are older than 7 days

docker-compose exec dovecot-mailcow doveadm expunge -A mailbox 'Junk' savedbefore 7d

Delete all mails (of all users) in all folders that are older than 52 weeks (internal date of the mail, not the date it was saved on the system => before instead of savedbefore). Useful for deleting very old mails on all users and folders (thus especially useful for GDPR-compliance).

docker-compose exec dovecot-mailcow doveadm expunge -A mailbox % before 52w

Delete mails inside a custom folder inside a user's inbox that are not flagged and older than 2 weeks

docker-compose exec dovecot-mailcow doveadm expunge -u 'mailbox@example.com' mailbox 'INBOX/custom-folder' not FLAGGED not SINCE 2w

!!! info For possible time spans or search keys have a look at man doveadm-search-query

Make it automatic

via the host system cron:

If you want to automate such a task you can create a cron job on your host that calls a script like the one below:

#!/bin/bash
# Path to mailcow-dockerized, e.g. /opt/mailcow-dockerized
cd /path/to/your/mailcow-dockerized

/usr/local/bin/docker-compose exec -T dovecot-mailcow doveadm expunge -A mailbox 'Junk' savedbefore 2w
/usr/local/bin/docker-compose exec -T dovecot-mailcow doveadm expunge -A mailbox 'Junk' SEEN not SINCE 12h
[...]

To create a cron job you may execute crontab -e and insert something like the following to execute a script:

# Execute everyday at 04:00 A.M.
0 4 * * * /path/to/your/expunge_mailboxes.sh

via Docker (Ofelia)

If you prefer to do it via Docker, you can do it with mcuadros/ofelia which is a low memory foot print docker job scheduler written in Go. It's quite easy to setup, first of all you need a Ofelia container running on your host (one container works for all other containers). To do so, you can add this to your mailcow docker.override.yml:

  ofelia:
    image: mcuadros/ofelia:latest
    restart: always
    command: daemon --docker
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro   
    network_mode: none

Ofelia doesn't need any network access, but access to the docker control socket to access the other containers. Once Ofelia is running by either adding it via the docker-compose.override.yml, or you running it otherwise, we can go and add the new job labels to the dovecot-mailcow container. I show here an example where I clean out the trash folder from any mails older then 2 weeks every day at 4 am.

  dovecot-mailcow:
    labels:
      - "ofelia.enabled=true"
      - "ofelia.job-exec.dovecot-expunge-trash.schedule=0 4 * * *"
      - "ofelia.job-exec.dovecot-expunge-trash.command=doveadm expunge -A mailbox 'Junk' savedbefore 2w"
      - "ofelia.job-exec.dovecot-expunge-trash.tty=false"

Add those lines to the docker-compose.override.yml of your mailcow or if you modified the dovecot definition already, extend the labels. The first one is clear, turns on Ofelia for this container. Next we have our cron-style time definiton, important here is also that part after ".job-execute." is the individual job name. This is important when you add more jobs to this container. Those of us who struggle with the cron definitions, i can suggest crontab guru which gives you much more of a gasp on the time string defintion. Next line is the command, which is similar to above to clean out the trash. We don't need to name the container here as that is pointed out by Ofelia by the label already. "tty=false" tells Ofelia we don't need a pseudo-terminal to runs this.

To see if things ran proper, you can not only see in your mailbox but also check Ofelia's docker log if it looks something like this:

common.go:124 ▶ NOTICE [Job "dovecot-expunge-trash" (8759567efa66)] Started - doveadm expunge -A mailbox 'Junk' savedbefore 2w,
common.go:124 ▶ NOTICE [Job "dovecot-expunge-trash" (8759567efa66)] Finished in "285.032291ms", failed: false, skipped: false, error: none,

If it failed it will say so and give you the output of the doveadm in the log to make it easy on you to debug.