[Greylist-users] Greylisting status

[Evan Harris]

On Wed, 9 Jul 2003, Alan Batie wrote:

> Greylisting has been a godsend here; before greylisting, I personally
> had about 1000+/- spams/day filtered by spamassassin, with about 15
> leaking.  After installing the greylisting milter, that's dropped to
> around 100, with only 2-3 leaking through.  Granted, some of my email
> addresses are over 10 years old, so I'm a worst case, but with around
> 500 users on the system, spam processing has been a major load.

Glad to hear it!  Have an estimate of total mails sent per day before and
after?

> On the down side, I noticed today that I'm seeing delays on mail injected
> locally, even though I have the whitelist configured.  This seems to be
> preventing the occasional mail from being delivered.

I'm not sure what you you mean.  Can you get a little more specific about
this problem?

>  I went to run the
> db_maintenance.pl script, and got an error about no more connections
> available, even though I could connect with the mysql client and run
> queries ok.  I ended up shutting down sendmail (to keep spam from coming
> in in the meantime), mysql and relaydelay, running the db_maintenance.pl
> script, then restarting things.  I think something's not freeing up
> threads in mysql (admittedly 4.1.0 alpha), though why it's dependent on
> database size instead of connections, I've no idea...

It's probably because you have large spam waves coming in that causes a
large number of sendmail children to run at the same time, which in turn
causes the milter to spawn more copies of itself.  Each copy consumes a db
connection.

An easy solution is to limit the sendmail children to some reasonable number
for your normal mail load.  Add:

   define(`confMAX_DAEMON_CHILDREN', `40')dnl

To your sendmail.mc and recompile.  You shouldn't have the problem again.

I've added a note about this problem to the INSTALL file, which will go out
with the next release (which I expect in a few days).  Having so many copies
of the milter running also consumes large amounts of memory, which is a
problem for some people with smaller amounts of memory/swap.  This is an
easy fix for that as well.

Evan