I am trying to configure replication between two host, both hosts are having the same errors. Using ‘dovecot log errors’ gives the following errors;

Dec 11 18:05:12 Error: auth: Trying to iterate users, but userdbs don't support it (created 0 msecs ago, handshake 0 msecs ago)

Dec 11 18:05:12 Error: replicator: User listing returned failure

Dec 11 18:05:12 Error: replicator: listing users failed, can't replicate existing data