No MX record drops mail

Danny Mayer mayer at
Sat Jun 8 15:42:47 UTC 2002

At 10:18 PM 6/6/02, Nanaya Dam Byznis wrote:

>Robert Case <consulting at> wrote in message 
>news:<3CFF2339.4080805 at>...
> > I get the feeling what's going on may not be on your end, but on the
> > receiving end of your e-mails;
> is the RCPT TO: , not the MAIL TO:
>His DNS is misconfigured and refuses to acknowledge this
>Our server is the one that drops mail to domains without an MX record

An MX record is NOT required for SMTP to deliver mail provided that the given
FQDN has a valid A or AAAA record and is able to receive mail.
Your server is misconfigured.  Please read the appropriate mail RFC's.

>He claims we are the *only* ones having this problem with him (sending
>i then opend a couple of free email accounts on the outside and yes
>was able to successfully send him mail
>This to me only proves that those free email webmails do not require
>an MX record prior to SMTP service
>But since we could not prove that the problem is his, and since
>outside mail services could send him mail, i was forced against my
>will to remove the ruleset that requires MX record validation.
>i removed the line
>dnl # define(`_RELAY_MX_SERVED_', 1)dnl
>from the mc file, but i still get returned mail
><<< 450 4.7.1 <wang_wz at>... Can not check MX records for
>recipient host
><user at>... Deferred: 450 4.7.1 <user at>... Can not
>check MX records for recipient host
>if an MX record truly exists for this domain why can't my DNS find it?
>  is it my problem or his?

An MX record is not required to exist.

>Here's a shot in the dark: is it possible he's using that Win2000

That's irrelevant, you have a misconfigured mail server.


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