Nigel Wade wrote: > Richard Hobbs wrote: > > - Once exim heavy is running (and exiscan is therefore enabled) I need to > > setup the ACL stuff to allow exim to run spamassassin, but only if the > > user's preferences exist. > > The problem with running per-user spam checking in an ACL is that you need > to restrict messages to single recipients. This is wasteful of bandwidth > both for you and the sending MTA when messages are originally sent with > multiple recipients - the message has to be resent for each recipient. This > applies to all messages, whether any of the recipients want spam checking or > not.
The other problem is that per-user scanning is also wasteful of system resources. At work before I migrated them to exim (from qmail), we had 5 spamd servers serving about 90 mail servers. The spamd servers had a 15 minute load average above 15 for most of the day and scan times were in excess of 40 seconds. Since the move to exim, Those 5 spamd servers are serving about 130 (growth in the mean time) mail servers and their load hardly ever goes over 1. Ian -- Ian Freislich -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
