I have a Zimbra installation running on Centos 6.6:
Release 8.6.0_GA_1153.RHEL6_64_20141215151155 RHEL6_64 FOSS edition.
I have one account on the server that receives mail forwarded from another server which is derived from a ticketing system and a considerable amount doesn't get delivered. The inbound mail only comes from three addresses, which I have whitelisted in the account. I can see that the mail is getting delivered by tailing /var/log/zimbra.log and that mails that don't reach the inbox seem to get the message
NOQUEUE: filter: RCPT from xxx.xxxx.com[xx.xx.xx.x]: <support@xxx.com>: Sender address triggers FILTER smtp-amavis:
[127.0.0.1]:10026; from=<support@xxx.com> to=<xxx@xxx.co.uk> proto=ESMTP helo=<xxx.xxx.com>
The mail can be tracked through the log:
Jul 23 16:15:38 ns3002961 postfix/smtpd[28408]: 72BEFA3776: client=xxx.xxx.com[74.63.41.50]
Jul 23 16:15:38 ns3002961 postfix/cleanup[28410]: 72BEFA3776: message-id=<nry29p.3h7nbr@secure.xxx.com>
Jul 23 16:15:38 ns3002961 postfix/qmgr[28883]: 72BEFA3776: from=<support@xxx.com>, size=2292, nrcpt=1 (queue active)
Jul 23 16:15:38 ns3002961 amavis[27867]: (27867-15) Passed CLEAN {RelayedInternal}, ORIGINATING LOCAL [74.63.41.50]:28770 [74.63.41.50] <support@xxx.com> -> <xxx@xxx.co.uk>, Queue-ID: 72BEFA3776, Message-ID: <nry29p.3h7nbr@secure.xxx.com>, mail_id: VcJMRzM4207u, Hits: -, size: 2351, queued_as: A88BDA3D77, 147 ms
Jul 23 16:15:38 ns3002961 postfix/smtp[28413]: 72BEFA3776: to=<xxxx@xxx.co.uk>, relay=127.0.0.1[127.0.0.1]:10026, delay=0.29, delays=0.14/0/0/0.15, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as A88BDA3D77)
Jul 23 16:15:38 ns3002961 postfix/qmgr[28883]: 72BEFA3776: removed
but doesn't arrive at the inbox. In a couple of instances it seemed like there might be a banned word filter operating because the originating addresses of the mails (the clients who send the mail) contained words that could be regarded as part of a spam mail, and whitelisting them has actually worked, but the issue is inconsistent and will fail to deliver mails even when other mails from the same user have been delivered.
I have run
zmprov ms `zmhostname` zimbraMtaLmtpHostLookup native
as suggested here and I have the option of turning off spam altogether for the account but I want to know why it's being blackholed and not being delivered anywhere if that's an option, and if logging can be improved as I'm not getting a reason why the mail isn't being delivered.