RE: exim4-light vs exim4-heavy
> From: Dave Ewart [mailto:firstname.lastname@example.org]
> Sent: Sunday, September 25, 2005 10:18 AM
> Well, yes: but that applies regardless of whether you've launching it
> from procmail or not :-)
Well, not exactly. I don't know enough about Exim to know if it can operate
this way, but if you do your AV/content filtering during the SMTP
transaction, you can reject with a 550 at the end of data. That is a lot
better than silently discarding messages after accepting them. Yes, that
keeps the TCP connection open a long time, but for a small to medium sized
system, that should not be a big issue.
The real savings is in rejecting before data based on a variety of measures,
terminating the connection much sooner and saving a lot of bandwidth. If
you do enough of that, you can cut down the number of messages that you
allow to go into data, and thus require AV/content filtering, to the point
that it is much less of a load on the system.