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 retraining
the keyboardist not to use multiple headers) would be to programmatically
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 resolve
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 outbound
delivery
And yes, I'm doing mail relying via panix (and others), but the bounces aren'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
https://www.flickr.com/photos/rmsppu
