Steven P Valli?re:
> I've noticed a fair number of messages list the one below
> in my mail logs:
>
>
> Jul 20 09:52:17 mail postfix/smtpd[2352]: NOQUEUE: reject: RCPT from
> unknown[ww.xx.yy.zz]: 450 4.1.8 <[email protected]>: Sender
> address rejected: Domain not found; from=<[email protected]>
> to=<[email protected]> proto=ESMTP helo=<host.xxxxxxxx.com>
>
>
> When these messages were generated, I had reject_unknown_sender_domain
> included in my list of smtpd_sender_restrictions. That particular
> reject option is supposed to "reject sender from domain without A or
> MX record."
>
> Unfortunately, when I went to check on one of the domains (because a
> message I was expecting kept being rejected) I discovered that the IP
> address logged had both an MX and an A record. Except for the obvious
That usually means there is a local file permission problem with
DNS so that Postfix can't read resolv.conf, or that the domain has
multiple NS records, and one of the NS hosts is giving out bad
information.
> was being accepted. EXCEPT, the MX preference value is 0 (ZERO) for
> the domain whose mail is being rejected.
That is a total red herring, as far as Postfix is concerned.
Wietse
