On 2021-11-22 09:27 -0800, Will Yardley <mutt-...@veggiechinese.net> wrote: > On Mon, Nov 22, 2021 at 11:22:33AM -0600, Aaron Poffenberger wrote: > > I know this is related to Message-ID because if I go into muttrc(5) > > and put `set hostname="example.com"` and send again to > > u...@sbcglobal.net, the message goes through without issue. > > It's likely not related to the Message-Id. I'd guess that it's related > to the envelope from address and / or HELO hostname. > > maybe this bit: > https://gitlab.com/muttmua/mutt/-/blob/master/smtp.c#L435-438
I don't think it's happening here. The messages are enqueued by my MTA (example.com) which would be the hostname given with "ehlo", while the error messages come from sbcglobal.net. And as noted, I can set hostname to example.com in muttrc(5) and all is fine. > > I have never heard of a situation where a host required the hostname > portion of the Message-ID header to be resolvable. Agreed. It took me several years of frustration to figure out why some emails to sbcglobal.net failed, and others didn't. My "aha" moment came when an exchange with a friend @sbcglobal.net suddenly failed. I initiated a conversation using Mail.app on OSX to a friend. She replied. I read it on my laptop using mutt, and then replied. The initial email obviously went through. But the reply from my laptop failed. Looking at the headers of both messages I saw one notable difference: the Message-ID. Mail.app was using the same fqdn as my From address whil mutt was using my full hostname (host.example.com). > > /w > Cheers, --Aaron
