Re: SMTP server error message

[Stephen J. Turnbull]

Eli Zaretskii writes:

 > I will try that as well.  Are all 4XX codes indeed of this nature?

Yes, all 4xx codes are an invitation to try again, they indicate a
transient glitch with the server (server couldn't allocate memory,
spamchecker crashed, that kind of thing).

There's no way to know when the server expects the problem to get
fixed, but for smtpmail I would guess that if it isn't fixed in a few
seconds, you may as well give up, and try by hand later.  Having
smtpmail retry multiple times in the background over several hours is
probably more programming than it's worth.