"Suresh Ramasubramanian" <mallet@???> writes:
>> Hmm, would you mind looking up the way SMTP is supposed to work? MTAs
>> are expected to work this way. If no IP connection can be made to the
>> first MX, other MXes should be tried. As a result, SMTP mail delivery
>> is extremely robust, and certainly you don't want to change this.
>
> Show me just where it says "retry if you get a 5xx"
It doesn't, and that's part of the problem.
Some people use the 554 greeting to indicate "no mail under this
domain", some to say "please try the next MX".
