Mails forward to the bitbucket channel

Question

Dear all,
One of our customer complains that a mail sent to him (mail2.mydom)from another user (mail1)in the same domain has not
recieved to his mailbox. The store log entires were as below. There is a SMTP relay in front of the store and the logs at this server is also shown below.
Any advice on trouble shooting what happens in this mail delivery ( through the bitbucket channel )is greatly appreciated.
smtp ( 192.168.6.210 )
====
20-Dec-2010 07:07:58.92 tcp_auth tcp_intranet EEA 4094 [email protected] rfc822;[email protected] @store.domain.com:[email protected] MAIL1 ([unknown] [123.45.67.89])
20-Dec-2010 07:08:00.48 tcp_intranet DEQC 4094 [email protected] rfc822;[email protected] @store.domain.com:[email protected] store.domain.com dns;store.domain.com (TCP|192.168.6.210|64313|192.168.6.212|25) smtp;250 2.1.5 [email protected] and options OK.
store ( 192.168.4.145 )
====
20-Dec-2010 07:12:16.61 tcp_intranet bitbucket EEC 4094 [email protected] rfc822;[email protected] mail2.mydom%example.com@ims-ms-daemon smtp1.domain.com ([unknown] [192.168.6.210])
20-Dec-2010 07:12:16.61 bitbucket DEC 4094 [email protected] rfc822;[email protected] mail2.mydom%example.com@ims-ms-daemon smtp1.domain.com ([unknown] [192.168.6.210])
Note : 192.168.6.212 is a load balancer
Thanks,
Best Regards.

Answer 1

Q1. Can't this delevery error I posted has any connection with vacation autoreply configured?
It is not an "error", but yes, it could be related to autoreply. If you set these options in option.dat:
log_connection=3  (or make sure bit value 2 is set if log_connection is already specified)
log_process=1
log_message_id=1and do imsimta cnbuild; and imsimta restart; you should be able to trace the messages thru the log and see if this is perhaps a copy of a message related to autoreply.
Q2. When vacation auto reply is configured for a user, it just send a autoreply to the sender's mail address.  Then what is the real requirement of specifying a different address destined for the bitbucket channel?
The requirement is to prevent that copy from becoming a real message that would be delivered somewhere. The original message has been enqueued as normal. This "copy" is discarded, by sending it to the bitbucket channel, after the autoreply has been generated.
Q3. When a msg is directed to the bitbucket channel and when the msg is dequed ( DEC ) from this channel, does it mean the msg is discarded immediately?  Is'nt there any copy kept in the disk for a default grace period?
Yes, it is discarded immediately. Actually, it is never written to disk. No, there is no way to keep a copy of it. In fact, once you enable LOG_PROCESS you can see that the dequeue from bitbucket channel is actually performed by the process which enqueued it there. The bitbucket channel is a special channel used to discard the message. It does so in the most efficient manner possible.
Q4. What is the meaning of the modifier "Q" ( which is not defined in the modifier list ) in the above log.
http://wikis.sun.com/display/CommSuite/Managing+Logging#ManagingLogging-ManagingMTAMessageandConnectionLogs
"SMTP PIPELINING extension used (RFC 2920)"
Why a mail server decided to use "chunking" ( Modifier "C" )
Because the remote SMTP server advertised support of that option.