GMail SMTP: no authenticators available?

[Baron Fujimoto]

Our org's email is hosted by Gmail (via GSuite). I had been using neomutt (built from MacPorts) successfully for years. Recently though, I can no longer send email successfully using GMail's SMTP servers. I get the error, "No authenticators available". IMAP still works fine. This change occurred while I had a neomutt session open; it was working one day when I left, but the next day, no bueno.

Although I had been using neomutt above (because it's what's available as mutt in MacPorts), I also tried compiling and installing real mutt (2.0.4) from source and I am seeing the same behavior with real mutt as well[*].

I don't know if it's relevant, but prior to not working at all, I'd had to enter my password whenever I start mutt for IMAP access, as well as *each time* I wanted to send a message via the SMTP server.

The following in my muttrc was used successfully util this problem began:

set smtp_url = smtp://user@example.org@smtp.gmail.com

Where user at example.org is my hosted gmail address.

I also tried the following with the same results:

set smtp_url = smtp://user@example.org@smtp.gmail.com:587
set smtp_url = smtps://user@example.org@smtp.gmail.com

I haven't seen any other traffic about this on the list, so presumably it's not a general problem.

Any suggestions would be appreciated.

[*] Built on MacOS 11.1 with "./configure --enable-sidebar --enable-compressed --enable-imap --enable-smtp --enable-debug --enable-hcache --with-ssl=/opt/local --with-sasl=/opt/local"