We are hosting multiple domains on our Zimbra server, we have come across an issue where users from certain domains can't use the IM feature ( although everything appears to be setup OK when checking in the web UI and zmprov ), however they don't receive any initial buddy invites or messages at all.
This seems only to affect domains which have a DNS A record set for their domain.
Looking in the log I can see the following entry ( using domain.co.uk as example )
2009-05-16:2009-05-16 13:19:23,661 INFO [pool-6-thread-2]  im - Error trying to connect to remote server: domain.co.uk(DNS lookup: domain.co.uk:5269)
(Which gives me the impression that the IM uses DNS, rather than LDAP in order to determine the destination )
Has anyone came across this issue before, and can it be fixed?