The mailing list for listmasters using Sympa

[Serge Aumont <address@concealed>]

Le 20/12/10 22:35, Adam Bernstein a écrit :

Hmm, I wonder if maybe we aren't doing VERP very well. The way you have
it set up sounds a little different than what we have done.

We've got verp_rate set to 10% in sympa.conf, and a generic bounce
alias:

Yes, we're doing VERP in Postfix too, so it goes on everything, and even with the DKIM signing on everything too, we're still having no issues at all with load even during massive mailings to large lists.  Postfix seems very efficient at it, and in fact I believe we got deliverability benefits just from the fact that we were no longer doing SMTP batching; our deferral rates at Yahoo went down when we activated it.

It's very simple to set up -- we just modified the default sendmail_args in sympa.conf to add the "-XV" flag (for Postfix 2.3+), and in Postfix's main.cf added:

recipient_delimiter = +
propagate_unmatched_extensions = virtual

and I believe the Return-Path gets VERPed with the same format as Sympa would do (I've never quite made sure of this, but it can be customized if not).  We also have the bounce+ alias defined, so I believe we're getting all the benefits of Sympa's VERP processing even though it's actually Postfix generating it.

It's great that Sympa is adding these capabilities, but we are really liking the simplicity and elegance of having all low level sending-related functions handled at the lowest possible level, in the MTA.

In 6.2, VERP can used not only to identify the original subscriber related to a DSN but also which message a DSN is related to. It is used in conjunction with the capacity to request DSN at SMTP level. In that case, the list owner can view a tracking table showing the delivery status for each subscriber.  This feature use a VERP format that carry receipient but also the related message in the Return-Path.  Would that be compatible with postfix VERP ?

How ever, we are open to a contrib that would make VERP format compatible with postfix or any other MTA capability.

See attached screen copy of a tracking page.