I was having problems with postfix accepting a message that was addresses to 57,000 BCC’d recipients and was at a loss as to what was causing the problem.  I foolishly didn’t have verbose logging enabled before sending the message, so I didn’t have much in the way of logs.  Now, how to debug this without possibly sending lots of testing messages to the entire student body of the University.  Google wasn’t giving me anything, but I finally found the answer and am writing it down in the hopes that it helps someone.  What I wound up doing was setting up a content filter on the snmp service that redirects the mail to the discard service.

Change your smtp configuration to look like the following, then run /etc/init.d/postfix reload


smtp      inet  n       -       -       -       -       smtpd
-o content_filter=discard:dummy


Now I’m just waiting for the authorization to send some test messages to see if postfix accepts the mass mail successfully.