Too much deferred messages in Zimbra?
Having too much deffered messages in Zimbra Collaboration Suite? And this error usually happened when messages with big attachment is sent?
[root@mail ~]# grep deferred /var/log/maillog
Apr 10 05:32:09 mail2 postfix/smtp: 2EEF859C06A: to=<firstname.lastname@example.org>, relay=mx1.mail.sg1.yahoo.com[18.104.22.168]:25, delay=217976, delays=217793/0.02/0.4/183, dsn=4.4.2, status=deferred (conversation with mx1.mail.sg1.yahoo.com[22.214.171.124] timed out while sending message body)
The error is related to Postfix, one of the main Zimbra component. This is due to a message take too much time when sent to a recipient. Exceeding the timeout limit defined in the server. To solve the situation, we can increase the timeout limit.
To do this, edit a Postfix configuration file, main.cf.
sudo vim /opt/zimbra/postfix/conf/main.cf
.. and append these lines to the file. By default, Zimbra man.cf does not have these lines like in other Postfix mail server configuration.
smtp_data_done_timeout = 600s
smtp_data_init_timeout = 120s
smtp_data_xfer_timeout = 600s
The effective attributes should be smtp_data_xfer_timeout. The bigger the values, the better. But for me 600 should be enough. Restart the service to implement the new configuration. That should do the work.