On Fri, 14 Jun 2019 20:49:46 +0000, Jeff Beaird <[log in to unmask]>
wrote:

>Jun  9 03:36:26 smtp-p2 postfix/smtpd[18435]: connect from 
>listserv.wheaton.edu[192.138.89.115]
>Jun  9 03:36:26 smtp-p2 postfix/smtpd[18435]: NOQUEUE: reject: RCPT from 
>listserv.wheaton.edu[192.138.89.115]: 450 4.1.2 
><[log in to unmask]>: Recipient address rejected: Domain not 
>found; 

This is a bad address.  WHEAETON.EDU is clearly a mis-spelling so Postfix
should format a proper 'bounce' message and email that back to LISTSERV.

>from=<owner-remark-users*redacted*-redacted**WHEAETON*[log in to unmask]> 
>to=<[log in to unmask]> proto=ESMTP helo=<listserv>
>Jun  9 03:36:26 smtp-p2 postfix/smtpd[18435]: lost connection after RCPT 
>from listserv.wheaton.edu[192.138.89.115]
>Jun  9 03:36:26 smtp-p2 postfix/smtpd[18435]: disconnect from 
>listserv.wheaton.edu[192.138.89.115]

It looks like Postfix is not sending a proper bounce message back to
LISTSERV for this problem.  As suggested by someone else, you should
communicate with the LISTSERV Admin about this.

>I believe this is because Listserv tries to send via the SMTP server, 
>ignores the 450 response from the SMTP server, and tries over and over 
>again.

The SMTP sending part of LISTSERV (under unix) is rather 'simple minded' and
is basically a 'send and forget' engine.  It is not prepared to handle a 450
refusal during the transaction.  If Postfix would accept all mail from
LISTSERV unconditionally (i.e. without trying to validate the destination
domain during acceptance from LISTSERV, which is what it appears to be doing
in this case) and then later, when trying to deliver to the non-existant
domain, if Postfix would then format a proper 'bounce' message with
appropiate error codes and send that back to LISTSERV, then LISTSERV
can/will properly deal with the bad address.

(LISTSERV under Windows uses a separate SMTPW.exe sub-program for sending
outbound SMTP mail to a full-featured SMTP mailer.  Again this SMTPW
sub-program is similarly 'simple minded' and also is not prepared to handle
450 or other possible forms of refusal during the SMTP transaction.)

Basically, LISTSERV assumes that all outbound mail it sends (to a separate
full-featured SMTP mailer application that will perform the actual final
deliveries) will be accepted unconditionally and without exception by that
SMTP mailer application.  Then later, when the SMTP mailer application
attempts delivery to bad domains, or otherwise encounters refusals or
rejections, it is able to format proper 'bounce' message reports and send
them back to LISTSERV, which will then happily deal with them.

You might say this is a shortcoming in LISTSERV, but I don't think so.
LISTSERV (under any OS) has always been intended to be paired with a
separate full-featured SMTP mailer application that performs final
deliveries.  There are probably historical reasons for this as well as
practical ones.  Developing and maintaining a full-featured SMTP mailer
application is a big job what with changing standards and all, and is
already handled by a number of reliable applications, including the
venerable Postfix.  Why should L-Soft/LISTSERV attempt to re-invent the
wheel that is already round and rolling in the right direction?  ;-)

(Yes, I worked for L-Soft for 20 years so I am tooting the party line, but
this is pretty much true if you stop to think about it.)

############################

To unsubscribe from the LSTSRV-L list:
write to: mailto:[log in to unmask]
or click the following link:
http://peach.ease.lsoft.com/scripts/wa-PEACH.exe?SUBED1=LSTSRV-L&A=1