[Mimedefang] Mimedefang errors: What might be the cause?

[Kris Deugau]

Rick Aliwalas wrote:
> Are MX_MINIMUM and MX_MAXIMUM set to the defaults?  It's says in my config
> file (/etc/sysconfig/mimedefang) that "The default value of 2 is probably
>  too low".  I set them as follows:
> 
>     MX_MINIMUM=4
>     MX_MAXIMUM=30
> 
> I got the same errors as you when my machines were under load and bumping
> these values made everything happy happy.

Watch that you don't run yourself out of memory by bumping these up. 
Old estimates for "memory per slave" were ~16M IIRC, but I think I saw a 
recent recommendation to allow ~40M per slave.  If you're running a trim 
  mimedefang-filter with no SA or other addon Perl modules, 40M per 
slave is probably quite pessimistic and you can probably reduce that to 
~20-25M...  but with SA3.x, it may even be too optimistic and you'll 
need to allow 50M+.

Tuning sendmail's load-limiting options also helps keed MD from hitting 
its limits;  check through your sendmail.mc for these options:

define(`confQUEUE_LA', `2')dnl
define(`confREFUSE_LA', `7')dnl
define(`confCONNECTION_RATE_THROTTLE',`1')dnl
define(`confDELAY_LA', `2')dnl
define(`confBAD_RCPT_THROTTLE',`2')dnl

(These are numbers from a PII/400 192M server hosting ~30 domains, tuned 
slowly over a week or so while watching the mail logs.  I've only ever 
had to take more drastic action once - a badly broken remote system 
which initiated SMTP connections ~5 times per second without actually 
doing anything with them.  They got an iptables DROP entry.)

There may be other sendmail-level settings that can/should be tuned as 
well;  if you don't have a copy of the Bat Book, GET ONE!  I've found it 
invaluable in tracking down some of these options.

-kgd