On Wed 30 Sep 2026 at 22:04:07 (-0400), Greg Wooledge wrote: > On Wed, Sep 30, 2026 at 17:48:07 -0500, David Wright wrote: > > I no longer use exim to queue outgoing external emails, as attachments > > are transferred so quickly that mutt isn't held up for any significant > > period of time. So my emails like this one get sent directly to a > > submission port at my email hosting service. > > > > I assume mutt (MUA) gets its HELO from /etc/hosts. > > I've never used mutt in that way, so I don't know where it gets its > configuration. The online documentation for mutt's SMTP doesn't > say much at all: > > <http://mutt.org/doc/manual/#smtp>
[ … ] > That's literally the whole documentation. > > If you want to dig into this, you could trace an SMTP session with > something like tcpdump, or look in the logs on a receiving SMTP machine > to which you have access, or check the full headers on a message sent > via mutt's SMTP, or ask on a mutt mailing list. I have dug into this twice in the past, firstly long enough ago that things were still being submited through exim, so irrelevant, and secondly last year using direct submission from mutt. But in the latter case, it was when I was being blocked from posting to debian.org, so I was keeping everything prim and proper. But last night, before I closed down, I altered /etc/mailname manually: $ cat /etc/mailname argo.c0rp $ and you can see the results on this post (I predict), and my previous one this morning in another thread: Received: from argo.c0rp [ … ] Message-ID: <[email protected]> and I can see in the maximum debug output from mutt: [2026-10-01 09:25:32] 6> EHLO argo.c0rp [2026-10-01 09:25:33] 6> Message-ID: <[email protected]> So my guess was wrong. I found mutt's sole mention of mailname in /etc/Muttrc: # If Mutt is unable to determine your site's domain name correctly, you can # set the default here. (better: fix /etc/mailname) # # set hostname=cs.hmc.edu The manual, /usr/share/doc/mutt/manual.txt.gz, doesn't mention using mailname at all; the important part of hostname determination is given as: Its value is determined at startup as follows: the node's hostname is first determined by the uname(3) function. The domain is then looked up using the gethostname(2) and getaddrinfo(3) functions. If those calls are unable to determine the domain, the full value returned by uname is used. Optionally, Mutt can be compiled with a fixed domain name in which case a detected one is not used. Starting in Mutt 2.0, the operations described in the previous paragraph are performed after the muttrc is processed, instead of beforehand. This way, if the DNS operations are creating delays at startup, you can avoid those by manually setting the value in your muttrc. I don't know whether Debian compiles mutt to know about mailname. Cheers, David.
