I have a clustered pair of mailbox servers (RHEL 4 cluster suite, basically following the Zimbra instructions for that) and a pair of MTA servers that are not part of the cluster, but are part of the same Zimbra installation. When I'm running on the primary mailbox server, the MTAs are not shown on the "Server Status" screen in the admin console. There are no error messages displayed; the servers are just not listed at all. However, when I fail over to the standby server, the MTAs show up properly on the "Server Status" screen. When I fail back to the primary, they are gone again. This does not seem to affect the operation of anything else, but it is weird and annoying.
I have gone through /var/log/zimbra.log and /opt/zimbra/log/mailbox.log and I don't see anything that points to the cause of this problem. Any ideas? Thanks,