Trying to plan a migration from qmail-ldap to Zimba. I have followed the various topics in the forums in relation to qmqp but have now hit a brick wall when trying to send messages. Here is the scenario.

The qmail-ldap server ( is the MTA for and has ldapclustering configured and working correctly. The Zimbra server ( has the following in :-

qmqpd_authorized_clients =
qmqpd_error_delay = 1s
qmqpd_timeout = 300s
qmqpd_client_port_logging = yes

and the following line added in :-

628 inet n - n - - qmqpd

I change the 'mailhost' ldap entry for from to I then send a message from to the migrated

From /var/log/zimbra.log I see:-

Nov 17 11:37:55 Zimbra postfix/qmqpd[1225]: 4359D3804DB: unknown[]:48214: netstring format error while receiving QMQP packet header

The message is returned to with the following error:-

Unable to cluster-forward message: mail server permanently rejected message (#5.3.0).

I am thinking maybe a problem with Postfix, but I cannot progress any further. Any help would be greatly appreciated.