Ever since updating my gateway to Fedora 7, I’ve been getting messages like this in my daily Logwatch:
84 *Warning: Pre-queue content-filter connection overload
Worrying that I might be losing mail, I looked at the logwatch script for postfix in
/usr/share/logwatch/scripts/services/postfix, and discovered that this message refers to lost connections from clients whose IP addresses are unknown – in other words, entries in the postfix log that look like this:
Aug 24 19:44:17 gateway postfix/smtpd: lost connection after CONNECT from unknown[unknown]
This happens when postfix doesn’t know the IP address of the client, probably because the client is “disconnecting” before the connection to postfix is properly established.