Re: suggestions for altering outbound SMTP to work-around multi-CC denials

[email protected] Mon, 23 Feb 2026 12:25:22 -0500
Newsgroups gmane.mail.nmh.devel
Message-ID <[email protected]_.yMu8>
Following up on the many(!) replies:

A more accurate description of the issue is that google and verizon bounce=
 mail back when there are multiple "CC" or "To" _headers_ (as per
RFC 5322), not just multiple recipients. The best solution (after retraini=
ng the keyboardist not to use multiple headers) would be to programmatical=
ly
condense headers (ie., combine the content of each CC header into a single=
 CC line). Ideally, this would happen as a filter operation after the MUA =
and
before my local MTA hands the message to the outbound rely. This would res=
olve the problem even if it arises from a message not composed with
nmh (ie., claws-mail, command-line, or a local daemon). I dunno if postfix=
 can condense headers this way, or perhaps I can wrap localhost:SMTP in a =
script
(using scan & anno?!) and then send the altered message to postfix for out=
bound delivery

And yes, I'm doing mail relying via panix (and others), but the bounces ar=
en't due to SPK or DKIM records.


Many thanks,

Mark

-- =

Mark Bergman    Biker, Rock Climber, SCUBA Diver, Unix mechanic, IATSE #1 =
Stagehand
'94 Yamaha GTS1000A^1					   2023 Triumph GT Explorer
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