Daniele Nicolodi:
> Hello,
>
> I have been using
>
> smtpd_relay_restrictions =
> ...
> reject_unknown_reverse_client_hostname
All features like this can block legitimate email. There is no
guarantee that someone won't break a good configuration, especially
when MAIL, DNS, and FIREWALL are managed by different people. Yes,
they might discover their mistake, but it is unlikely that they
will resend bounced mail.
I have "warn_if_reject reject_unknown_reverse_client_hostname" to
test the waters, and I don't feel an urge to make that a hard reject.
Generally I prefer to 'hold' suspect mail if there is a possibility
of collateral damage. But that works only on a small scale.
Wietse
