[Mailman-Users] MS Exchange as a relay computer?

alex wetmore alex at phred.org
Tue Jan 28 17:10:14 CET 2003

On Tue, 28 Jan 2003, Jonathan Knight wrote:
> > >                                                         Exchange can
> > > send a single message to handle all of those recipients instead of
> > > sending 5 or 10 as would occur when using the recommended batching of
> > > 10 recipients per message for postfix and other popular Unix-based
> > > MTAs.
> > This is not true for postfix.
> That's not true for exim either.  It's a configurable option so that those
> MTA's which refuse messages with more than X recipients (to avoid some spam)
> can be catered for.  Exim can be configured with different limits for
> different domains.
> > > Exchange 2000 has no problem sending the same message to multiple
> > > domains at the same time.  The remote deliver agent on most Unix MTAs
> > > can only send to one domain at a time
> >
> > This is not true for postfix.
> Nor for exim.  It's a configurable option.

Sorry for the misinformation.  I was going by some information that I
learned on this list about two years ago stating that setting
MAX_SMTP_RCPTS to between 5 and 10 will increase parallelism with the

Will exim and postfix both open multiple connections to a remote
domain when there are many recipients for that domain on a single

The Mailman FAQ still recommends setting MAX_SMTP_RCPTS to 10 for
performance reasons, but doesn't explain why.


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