On 17.7.2010, at 14.29, Daniel Luttermann wrote:

Quote from wiki page:

===== Expunging a message only decreases the message's refcount. The space is later freed in "purge" step. This may be done automatically within the session or later in a nightly cronjob when there's less disk I/O.

There is currently no automatic purge. I updated the wiki.

So this means that even if a user deletes a mail the space gets only freed if I run "doveadm purge" manually

Right.

or an user requests this over his mail client?

User can't request this.

When the expunge plugin is used the deleted mails are stored in a special mailbox in the users mailbox so it's needed to use the expire plugin too if this should be done automatically?

Do you mean lazy_expunge plugin? The expunged mails aren't automatically deleted, so yes, you'll need to delete them. Expire plugin isn't necessary, but it can optimize to skip users who don't have anything to expunge.

Is it recommend to run "doveadm purge" periodically if mdbox is used?

If you don't want to use up all your disk space, yes :)

Btw: when I try to run

doveadm -Dv expunge -u testuser@dlutt.de mailbox Trash savedbefore 30d

doveadm(root): Error: dlopen(/usr/lib/dovecot/modules/doveadm/lib10_doveadm_expire_plugin.so) failed: /usr/lib/dovecot/modules/doveadm/lib10_doveadm_expire_plugin.so: undefined symbol: expire_set_lookup doveadm(root): Error: dlopen(/usr/lib/dovecot/modules/doveadm/lib10_doveadm_quota_plugin.so) failed: /usr/lib/dovecot/modules/doveadm/lib10_doveadm_quota_plugin.so: undefined symbol: quota_user_module

Plugin expire or expunge is not currently enabled in Dovecot's config.

That's intentional. They aren't really errors and they're not visible if you don't give -D parameter. doveadm just tries to load all plugins and ignores the ones that it can't (because you haven't enabled expire or quota in mail_plugins).