Minimum hardware capacity for 35k e-mail scans/day

Greg Matthews gmatt at
Thu Nov 15 10:52:56 GMT 2007

Edward Prendergast wrote:
> Any advice from the vast pool of MailScanner experience would be greatly
> appreciated.

- reject more at the MTA - consider a block list
- double the memory to 4GB - it will get used and its much faster than disk.
- run a caching name service daemon - high load may be due to iowait. 
Also, consider reducing the number of DNS lookups performed by SA.
- check to see if you are running pyzor and try removing it - more long 
DNS queries to drive up the load.
- remove IMAP services - this can really kill a busy server, separate 
out your mail filtering from your mail delivery

Your dual Xeons should be able to handle that level of mail. That said, 
I have a client that runs a busy IMAP server alongside MS on a much more 
powerful box and I had to impose limits on the imap connections as 
certain clients were killing the performance when churning through large 

Are you queues actually building up or are you just concerned with the 
load average?

Greg Matthews           01491 692445
Head of UNIX/Linux, iTSS Wallingford

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