> Olivier M. wrote:
> > Are there some unwanted effects to reject mails using this
> > kind of method ? thanks for your hints & a nice week to you!
Yes. If you are unable to resolve the domain name (your resolver is down,
the domains DNS is unavailable and you don't have the info cached, etc)
you will reject valid mail.
Thus, domain doesn't exist -> 5xx permanent error
domain name can't be resolved -> 4xx deferral
We see this commonly with mailing lists and crappy setups at the receiving
end (no DNS on SMTPD host and DNS resolution time > SMTP RCPT timeout).
They reject the message even though our DNS is correct and available.
--
-Sincerely, Fred
Fred Lindberg, Inf. Dis., WashU, St. Louis, MO, USA
