[Mailman-Users] Mailman speed

Brad Knowles brad.knowles at skynet.be
Thu Jul 8 21:33:42 CEST 2004

At 5:43 PM +0100 2004-07-08, Ian A B Eiloart wrote:

>  Anyway, exim won't be queueing mail AFTER doing the VERP. Only the
>  un-VERPED message gets queued.

	Which is the point.  Doing the VERP in Mailman means that 
multiple messages would get queued, one for each recipient.  If you 
queue the message first and then do the VERP afterwards, that will 
avoid the synchronous meta-data update operations for all those 
additional recipients.

>                                 EXIM's philosophy is to avoid queueing
>  messages if possible, because it is usually possible to deliver a
>  message at the first attempt. Probably better than 99% likelihood for
>  a typical mix of domains.

	My experience is that 90-99% of initial delivery attempts are 
successful, which seems to match with the philosophy of Exim.

>  At least, I think that's the way it works. The strategy probably
>  wouldn't work with an MTA like qmail which queues first and thinks
>  later.

	Which was my point behind the statement that this would depend on 
the MTA implementation.

>>  	Of course, this does assume that the MTA uses the same VERP format that
>>  Mailman would have used, otherwise Mailman is likely to get very
>>  confused.  This may or may not pose a problem for you, but you should at
>>  least check to make sure that they both use the same formats.
>  Of course it does! The whole point of the recipe is to deliver Mailman
>  like VERP without the overhead in handoff of messages from Mailman to
>  the MTA.

	But you've got to make sure that the VERP format is the same. 
And how do you deal with recipient addresses which are themselves 
VERPed?  How do you take a VERPed recipient address and then VERP 
that for inclusion in the envelope sender address?

Brad Knowles, <brad.knowles at skynet.be>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

More information about the Mailman-Users mailing list