problem delivering mail

[janiceitit]

In these days I noticed I lost a lot of e-mails. Apparently mail are sent correctly, but they haven't been delivered in users' mailboxes.
If I check mailbox.log I find this:

2009-04-24 12:24:13,413 INFO [LmtpServer-372] [ip=x.x.x.x;] lmtp - Delivering message: size=2971 bytes, nrcpts=1, sender=user1@mydomain.com, msgid=<!&!AAAAAAAAAAAYAAAAAAAAAJS9LDrQ/uNBqj6uTL1KlK/CgAAAEAAAAEPV9VWF5pdKjxsLLYhdYSUBAAAAAA==@mydomain .com>
2009-04-24 12:24:13,413 INFO [LmtpServer-372] [name=user2@mydomain.com;mid=20;] lmtp - Not delivering message with duplicate Message-ID <!&!AAAAAAAAAAAYAAAAAAAAAJS9LDrQ/uNBqj6uTL1KlK/CgAAAEAAAAEPV9VWF5pdKjxsLLYhdYSUBAAAAAA==@mydomain .com>

I noticed this problem in two different zimbra server.

The bad thing is that user are not aware of undeliverable mail, If i didn't check log after users complaint I wouldnt' be aware of that.

[phoenix]

Message disappears between MTA and mailbox server

[janiceitit]

I just read this post before posting my problem. I did that because the problem hasn't been solved

[janiceitit]

UP.
Problem not still solved

[janiceitit]

How can I change zimbraMessageIdDedupeCacheSize ?
From: lmtp - Not delivering message with duplicate Message-ID

[janiceitit]

My Problem is still not solved.
How is it possible that main function of a mail server, such as delivering mail, is not performed correctly?
At the moment, some sent mail are thrown away without any notification to the sender! Incredible!

[uxbod]

It would also help us if you said which version of ZCS you were running please

su - zimbra
zmcontrol -v

[janiceitit]

Thank you for your reply.
Release 5.0.5_GA_2201.UBUNTU6_64 UBUNTU6_64 FOSS edition

installed on an Ubuntu 8.04 64-bit

If you need other informations, pleas ask me.

Thanks