lost connection after CONNECT

[hcyuan]

I'm running Postfix 2.2.9 on SLES 10. I have MAIA Mailguard setup on this server and everything was running great as of this morning. This morning, I decided to add in rules du jour and add some sender/recipient restrictions. Stupid me, I did all these updates at the same time.

After completing all the update, I'm seeing a lot of "lost connection after CONNECT" errors. Mail servers (both good and bad) will (according to the log) connect to my server, and then disconnect almost immediately. No mail ever gets transferred.

My suspicion is that after doing Rules Du Jour, there are too many rules that it needs to scan through per email that it's slowing down Postfix and is unable to accept new connections. Maybe something like that. Anybody have any ideas on how to fix this? Maybe how to remove all the rules that SpamAssassin is using and get it to start fresh again?

Thanx in advance.
Nuri

 

[hcyuan]

I found the answer to the problem and since I've never found any posts online about how to fix this problem, I'm posting this...hopefully to help out the next guy/gal.

Reason for getting a bunch of "lost connection after CONNECT from xxxx" was not because of too much rules for scanning (although you could say it is that) was because Postfix was not tuned correctly. By default, Postfix is configured (in master.cf) to accept 2 connections at a time.

So what my server was doing was that Postfix would allow two connections at a time to receive email, in which it passes to amavisd (which was also configured for two connections by default) for scanning for spam/virus.

My site receives a lot of emails and this caused all the error messages. The problem was fixed after I went in and increased amavisd's server threads to 15 and Postfix up to 30. The configurations may be more than I need...but I figure better safe than sorry. This now allows my Postfix to receive 30 connections at a time and it won't get backed up since amavisd now has 15 threads to use to scan for spam/virus.

The only error messages I get now are "lost connection after RCPT from xxxx" which is resulted from Postfix rejecting email to an unverified recipient.

Hopefully, this will help others out there if they ever run into this same problem.