Re: SMTP server error message

[Eli Zaretskii]

> From: "Stephen J. Turnbull" <address@hidden>
> Cc: address@hidden
> Date: Sun, 01 Jun 2014 03:18:11 +0900
> 
> 451 means an intermittent problem at your ISP.  The "one broken node
> in the cluster" hypothesis sounds plausible to me, but in any case
> since the server is at your ISP, they should fix their server.  It's
> not smtpmail, since the transaction is completing with a proper
> response code, it's the server.

OK, I guess I'll collect the names of the servers that return this
error, and if they are the same every time, will send a note to
postmaster.

> To save you (and maybe others) some grief, smtpmail could retry on any
> status code matching "4[0-9][0-9]", that's what an SMTP client is
> supposed to do.  Probably in most cases waiting a few seconds and
> trying once should be enough when you're talking only to your ISP.

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