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

[Gary Funck]

> From:David F. Skoll
> Sent: Monday, January 16, 2006 8:58 AM
>
>
> Kris Deugau wrote:
>
> > define(`confQUEUE_LA', `2')dnl
> > define(`confREFUSE_LA', `7')dnl
>
> Bad settings.
>
> Having REFUSE_LA higher than QUEUE_LA is a surefire way to kill
> your server.

Some handy tuning/debugging tips:
http://www.brandonhutchinson.com/Miscellaneous_Sendmail_notes.html

Quoting:

"rejecting connections on daemon MTA"
By default, Sendmail will reject MTA/MSA connections when the system load is
12 * number of processors, and operate in queue-only mode when system load
is 8 * number of processors.

egrep "QueueLA|RefuseLA" /etc/mail/sendmail.cf
#O QueueLA=8
#O RefuseLA=12

>From cf/README:

confQUEUE_LA            QueueLA         [varies] Load average at which
                                        queue-only function kicks in.
                                        Default values is (8 * numproc)
                                        where numproc is the number of
                                        processors online (if that can be
                                        determined).
confREFUSE_LA           RefuseLA        [varies] Load average at which
                                        incoming SMTP connections are
                                        refused.  Default values is (12 *
                                        numproc) where numproc is the
                                        number of processors online (if
                                        that can be determined).

For dedicated mail servers, the value of RefuseLA should be greater than the
value of QueueLA. Mail should not be accepted faster than it can be
processed, as mentioned in sendmail/TUNING:

It is important not to accept mail
faster than it can be delivered otherwise the system will be
overwhelmed.  Hence RefuseLA should be lower than QueueLA, the number
of daemon children should probably be lower than the number of queue
runnners (MaxChildren vs. MaxQueueChildren).

Also, read this comp.mail.sendmail post
http://groups.google.com/group/comp.mail.sendmail/msg/41d65caec2a4edb3?hl=en
&lr=&ie=UTF-8

On a dedicated mail server, you want to set QueueLA *higher* than
RefuseLA - the other way around will cause your queue to explode when
the load is high (assuming you reach QueueLA of course), you accept lots
of new messages but can't get rid of them as the load average hovers
around RefuseLA - the many messages in the queue drive up disk I/O and
thereby the load average.

The default of QueueLA lower than RefuseLA only makes sense for a server
that does other things besides mail, where you want to reduce the impact
of the mail load on the other functions by queuing instead of delivering
when the load is high.