Mailscanner scanning slowly

Daníel Kristinn Gunnarsson danielg at
Tue Mar 3 15:03:14 GMT 2009

Hi there !

Lately I've been running into some trouble with MailScanner + spamassassin. Let me explain my current setup.

I have a high-load mailserver (100k+ emails per day) that transfers all emails to 2 dedicated servers running Mailscanner + spamassassin for scanning. Both machines have the exact same setup:

SLES 9.3
4gb RAM
2x 64-bit Dual Core AMD Opteron running at 2ghz
MailScanner 4.71.10
SpamAssassin 3.2.5
Perl 5.8.3
Postfix 2.2.6

Both servers process almost equal amount of mail or about 50k each. The problem I'm having is that while server 2 is processing 10 mail scans in about ~60 secs, server 1 takes 300 secs to process them. Max unscanned and max unsafe messages per scan is set to 10 messages, no RBL checks set in MailScanner.conf, 10 children running and Delivery method is running in Batch, changing it to queue did nothing for me. I've tried lowering max children and messages per scanning batch but still it takes from 5 secs to 1 minute to scan a single message on server 1. CPU load goes from 0.4 to 0.8 on both servers. Any ideas, thoughts, tips and tricks are appreciated.

Daniel Kristinn Gunnarsson
Tæknimaður / Technician
Tækniborð / Technical Support
danielg at
+354 599-9500 - 3 

Skútuvogi 2
104 Reykjavík


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