[Mimedefang] Default SMTP code and dsn for filter_recipient() not standard compliant?

[David F. Skoll]

On Fri, 21 Jun 2013 11:51:58 +0200
Franz Schwartau <franz at electromail.org> wrote:

> After doing some tests I was wondering, why mimedefang returns
> 554 5.7.1 after a RCPT TO.

That's the default and it seemed reasonable to me at the time.
Although the RFC doesn't list 554 as a "usual" response to RCPT, it
does say:

   "SMTP clients SHOULD, when possible, interpret only the first digit
    of the reply and MUST be prepared to deal with unrecognized reply
    codes by interpreting the first digit only."

so I think the distinction between 550 and 554 is mostly of academic
interest.

Regards,

David.