[Mailman-Developers] Re: way to minimize IO load with MTA supported VERP

[Dan Mick]

"Barry A. Warsaw" wrote:
> 
> >>>>> "JCL" == J C Lawrence <claw@kanga.nu> writes:
> 
>     JCL> Mailman is going to end up with a set of MTA-specific and
>     JCL> internally configurable VERP configurations to chose from.
> 
> I actually don't think that MTA-directed VERPing helps us out much.
> Sure, it can give us an envelope sender that we can use for better
> bounce detection[*], 

...which is clearly all it's good for.  I have a significant percentage
of users whose bounces are useless without VERP, and it's tiring dealing
with the uncaught bounces.  If I can get VERP with little extra load
(because it's done in the MTA) then I'm happy.  (Been running for the last
8-10 hours with Postfix doing the VERPing, with a small hack to 
SMTPDirect.py, and some logging in BounceRunner.py, and it looks really
nice so far.)

> but I think that the much more interesting
> personalization is content personalization.  I.e. inserting into the
> message body, footers, headers, RFC 2822 headers, etc. information
> specific to the recipient.  Only Mailman knows that data and how to
> interpolate it into the message body.  AFAIK, there's no way to
> coordinate this with the MTA, so content personalization is always
> going to be performed by Mailman.

Sure.  But that's *expensive*.  It's stunning how much more time that
all uses up.  Granted, I haven't done the various spool vs. syslog 
optimizations etc., but the point is I don't have to until we get to
one-MLM-to-MTA-transaction-per-user.  That's when it gets brutal.

Anyway, the VERP-in-the-MTA thing seems like a useful featurelet, even
if it has limited benefit.  Hopefully more MTAs will follow.