Active queue keeps piling up

[fyd]

I am facing a delay in moving messages from active queue to user's mailboxes. As a result mails get stuck in active queue and takes a delay of 15 to 20 minutes to deliver. Tried sending a mail to myself. After checking the logs I find smptd as accepting the mails and waiting to get in touch with port 10024. Amavisd is taking a long to respond it seems.

[zimbra@ conf]$ grep DA0989F415A /var/log/zimbra.log
Aug 1 12:32:19 postfix/smtpd[21517]: DA0989F415A: client=mailstore.zimbra.com[xxxx]
Aug 1 12:32:19 postfix/cleanup[29778]: DA0989F415A: message-id=<14ad47df-9ae1-45ea-b3d5-e40548d3c527@mailstore.zimbra.com>
Aug 1 12:32:19 postfix/qmgr[20523]: DA0989F415A: from=<user@myserver.com>, size=581, nrcpt=1 (queue active)

delay ..

Aug 1 12:53:56 postfix/smtp[8203]: DA0989F415A: to=<user@myserver.com>, relay=127.0.0.1[127.0.0.1]:10024, conn_use=9, delay=1297, delays=0.01/1277/0/20, dsn=2.0.0, status=sent (250 2.0.0 Ok, id=07056-02-9, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as AAD349F4104)
Aug 1 12:53:56 postfix/qmgr[20523]: DA0989F415A: removed
[zimbra@ conf]$

During these time what happens is ..

[zimbra@ conf]$ grep AAD349F4104 /var/log/zimbra.log
Aug 1 12:53:56 postfix/smtpd[22102]: AAD349F4104: client=localhost.localdomain[127.0.0.1]
Aug 1 12:53:56 postfix/cleanup[11110]: AAD349F4104: message-id=<14ad47df-9ae1-45ea-b3d5-e40548d3c527@mailstore.zimbra.com>
Aug 1 12:53:56 postfix/qmgr[20523]: AAD349F4104: from=<user@myserver.com>, size=1218, nrcpt=1 (queue active)
Aug 1 12:53:56 amavis[7056]: (07056-02-9) FWD via SMTP: <user@myserver.com> -> <user@myserver.com>,BODY=7BIT 250 2.0.0 Ok, id=07056-02-9, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as AAD349F4104
Aug 1 12:53:56 amavis[7056]: (07056-02-9) Passed CLEAN, MYNETS LOCAL [xxxx] [xxxx] <user@myserver.com> -> <user@myserver.com>, Message-ID: <14ad47df-9ae1-45ea-b3d5-e40548d3c527@mailstore.zimbra.com>, mail_id: X+Hro8coDzBh, Hits: -2.91, size: 581, queued_as: AAD349F4104, 20160 ms
Aug 1 12:53:56 postfix/smtp[8203]: DA0989F415A: to=<user@myserver.com>, relay=127.0.0.1[127.0.0.1]:10024, conn_use=9, delay=1297, delays=0.01/1277/0/20, dsn=2.0.0, status=sent (250 2.0.0 Ok, id=07056-02-9, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as AAD349F4104)
Aug 1 12:54:04 postfix/lmtp[27791]: AAD349F4104: to=<user@myserver.com>, relay=mailstore.zimbra.com[xxxx]:7025, delay=8.1, delays=0.01/0/8/0.09, dsn=2.1.5, status=sent (250 2.1.5 Delivery OK)
Aug 1 12:54:04 postfix/qmgr[20523]: AAD349F4104: removed

I increased amavisd logging but there is nothing much fed to zimbra.log. So this can also be an issue with postfix. Can someone please guide me here?

[glitch23]

I'm having a very similar problem or the exact same problem but mine only seems to occur when there is a large number of people on a distribution list.

Did you have figure out what your problem was?

[fyd]

Originally Posted by glitch23

I'm having a very similar problem or the exact same problem but mine only seems to occur when there is a large number of people on a distribution list.

Did you have figure out what your problem was?

in my case it was a wrongly configured resolv.conf (dns) file. some ip was added to it, which postfix was trying to resolv to get the domain info. we checked it only when everything else was confirmed to be fine. lmtp was also affected because of the overhead.