According to wiki2.dovecot.org the problem is solved by removing the write persmissions to the group on /var/spool/mail/username.

Note: The locally running replicator allways pushes the local changes to the far side (provided it is running without the -R flag)

doveadm replicator status <username pattern>

<username pattern> is something like *@example.com, user@example.com, u* or just *

Times shown are the time passed since last fast/full sync.

doveadm replicator dsync-status

Accepts a username pattern as well, but works without it.

doveadmin replicator replicate -f <username pattern>

triggers a new full sync. (Needs to be called twice sometimes?)

doveadm force-resync is not related to replication!

Credits:

• https://wiki.dovecot.org/Replication

imap email dovect