Queue Problem - Deferred Inbound Issues

[tbridge]

Hi gang,

Having an odd problem post-4.5.10 where messages into the inbound queue remain there for a good 20-30 minutes sometimes, but other times, go just find. Here's what a deferred message looks like in the logs (fqdns changed to protect the innocent):

Dec 10 15:08:45 Zimbra postfix/smtpd[18812]: TLS connection established from someinboundemailserver..com[66.208.41.210]: TLSv1 with cipher AES128-SHA (128/128 bits)
Dec 10 15:08:45 Zimbra postfix/smtpd[18812]: DCB865CBBB48: client=someinboundipaddress.com[66.208.41.xx], sasl_method=PLAIN, sasl_username=cmiller@fqdn.ourdomain.com
Dec 10 15:08:45 Zimbra postfix/cleanup[18408]: DCB865CBBB48: message-id=<DD03E148-93C3-4083-9458-595C7BFC36CC@fqdn.ourdomain.com>
Dec 10 15:08:46 Zimbra postfix/qmgr[10321]: DCB865CBBB48: from=<cmiller@fqdn.ourdomain.com>, size=11460, nrcpt=1 (queue active)
Dec 10 15:08:55 Zimbra postfix/smtp[18797]: DCB865CBBB48: to=<rclark@fqdn.ourdomain.com>, relay=127.0.0.1[127.0.0.1], delay=10, status=sent (250 Ok: queued as 98CF85CBBB55)
Dec 10 15:08:55 Zimbra postfix/smtpd[18809]: 98CF85CBBB55: client=localhost[127.0.0.1]
Dec 10 15:08:55 Zimbra postfix/cleanup[18408]: 98CF85CBBB55: message-id=<DD03E148-93C3-4083-9458-595C7BFC36CC@fqdn.ourdomain.com>
Dec 10 15:08:55 Zimbra postfix/qmgr[10321]: 98CF85CBBB55: from=<cmiller@fqdn.ourdomain.com>, size=12054, nrcpt=1 (queue active)
Dec 10 15:08:55 Zimbra postfix/smtp[18797]: DCB865CBBB48: to=<rclark@fqdn.ourdomain.com>, relay=127.0.0.1[127.0.0.1], delay=10, status=sent (250 Ok: queued as 98CF85CBBB55)
Dec 10 15:10:10 Zimbra postfix/lmtp[18814]: 98CF85CBBB55: to=<rclark@fqdn.ourdomain.com>, relay=none, delay=75, status=deferred (Host or domain name not found. Name service error for name=fqdn.ourdomain.com type=A: Host not found, try again)
Dec 10 15:33:01 Zimbra postfix/qmgr[10321]: 98CF85CBBB55: from=<cmiller@fqdn.ourdomain.com>, size=12054, nrcpt=1 (queue active)
Dec 10 15:33:02 Zimbra postfix/lmtp[4447]: 98CF85CBBB55: to=<rclark@fqdn.ourdomain.com>, relay=fqdn.ourdomain.com[192.168.0.100], delay=1447, status=sent (250 2.1.5 OK)
Dec 10 15:33:02 Zimbra postfix/qmgr[10321]: 98CF85CBBB55: removed

So, it comes in, goes into the queue, and then promptly sits there for 30 minutes as deferred when the hostname "can't be found" even though this is how the hosts file for the local machine looks:

127.0.0.1       localhost
255.255.255.255 broadcasthost
192.168.0.100   fqdn.ourdomain.com
192.168.0.100   fqdn.oldcompanyname.com

Is there something I should be doing different? I'm fairly sure the /etc/hosts file is set up correctly, as we weren't having this issue under 10.4.x or 4.5.1-6.

Server is Mac OS X 10.4.11, Zimbra is 4.5.10, recently upgraded from 4.5.6.

Best,

Tom