SOLVED How is mdbox pruning / rotation handled?

Hello @brt,

The following settings in WHM >> Mailserver Configuration are relevant to the automatic deletion of emails in the Trash folders when using the mdbox format:

Auto Expunge Trash
Trash Expire Time

For deleted emails stored in the Trash folder, the emails are pruned from the mdbox files based on the Trash Expire Time value when Auto Expunge Trash is enabled. This happens when the following dovecot maintenance script runs during /scripts/upcp:

Code:

/usr/local/cpanel/scripts/dovecot_maintenance

As far as the general deletion of emails (e.g. when a user fully deletes the email and doesn't use the Trash folder), the mdbox files are updated to reflect the change when /usr/local/cpanel/scripts/dovecot_maintenance runs during /scripts/upcp.

Thank you.

 

Yes, this is correct.

The /usr/local/cpanel/scripts/dovecot_maintenance script (it runs nightly as part of the cPanel update cron job) automatically detects deleted emails and removes them from their corresponding mdbox files. For example, here's an example of an email account with several messages on a system with the default values (10M and 0) for MDBOX rotation size (MB) and MDBOX rotation interval (Weeks or Days):

Code:

# pwd
/home/user123/mail/domain.tld/test1/storage/
# du -s *
4   dovecot.map.index.log
2380   m.2

As you can see, it's not large enough to get rotated by the referenced settings. However, upon logging in to the email account and deleting a few messages, the mdbox files are reduced in space the next time /usr/local/cpanel/scripts/dovecot_maintenance runs:

Code:

# /usr/local/cpanel/scripts/dovecot_maintenance
[dovecot_maintenance] Setting I/O priority to reduce system load: best-effort: prio 7
Purging deleted messages for “user123” …Done
# du -s *
4    dovecot.map.index.log
2240    m.3

Thank you.