[Mailman-Users] Odd smtp-error

Rich West Rich.West at wesmo.com
Sun Oct 24 06:41:09 CEST 2004

Mark Sapiro wrote:

>>o In the sendmail logs, I get (just do the normal replacements for the 
>>words "at" and "dot"):
>>Oct 23 21:26:08 cranium sm-mta[13718]: i9O1Q8EF013718: 
>>from=<test-bounces+rich dot west=wesmo dot com at lists dot wesmo dot com>, 
>>size=1421, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=localhost 
>The above envelope from is VERP like.
>><..snip..> Weird.. I never had to alter [the value of SMTP_MAX_SESSIONS_PER_CONNECTION] before...  Will that have a 
>>negative impact on things in any way?!
>Yes, but not too much. The VERP like address above is used for enhanced
>bounce detection and is controlled by VERP_DELIVERY_INTERVAL and other

I went through the Defaults.py file and read up on VERP to get better 
acquainted. :)

>This is the big performance hit with VERP like envelope from because
>the message text must be repeated for each recipient as opposed to
>non-personalized, non-VERP which may have just one MAIL FROM:, a bunch
>of RCPT TO: and one DATA.
>In your case, setting SMTP_MAX_SESSIONS_PER_CONNECTION = 1 takes the
>above SMTP session with multiple transactions and puts QUIT, get
>disconnected, reconnect, EHLO between each message. This adds some
>impact, but not alot compared to the impact of doing the VERP like
>addressing at all.<..snip..>
>It seems like there is some problem with your MTA accepting multiple
>transactions per session or possibly with the way Mailman sends them.

Possibly.. I went looking through my mm_cfg.py and, at the end, the 
following VERP options had been enabled:

Basically, everything was turned on.  For sanity sake with regards to 
the testing, I set the value for SMTP_MAX_SESSIONS_PER_CONNECTION back 
to 0 in the Defaults.py file (since I really should have set it in 
mm_cfg.py anyhow), commented out the above values in the mm_cfg.py, 
recompiled, restarted mailman, and shot off a test email.

It came through with no problems.

So, I guess it is a toss up as to having VERP enabled with one SMTP 
connection per transaction or disabling VERP and setting the SMTP max 
sessions per connection to 0 (unlimited)...

Recommendations/suggestions? :)


More information about the Mailman-Users mailing list