SUMMARY: MX/A records; mail problems

From: Dave Zwieback (
Date: Mon Mar 30 1998 - 10:56:29 CST

The original question was:

> I have an MX record for our domain in the DNS. However, I don't have
> A record for
> Apparently, we can't get mail at sometimes from certain
> users.
> Would adding an A record would help? What would be the format, just
> " IN A address.of.mail.exchanger" ????

Unfortunately, there was no consensus. Some people said that if a mailer
can't recognize an MX record then it's broken. However, some people
suggested that I add an A record for in addition to an MX
record for will fix the problem for "brain dead mailers",
i.e.: IN A

The O'Reilly book on DNS (DNS and Bind, 2nd edition) implies that by
default most mailers will first look up the MX record for a particular
host, and then, if the lookup fails, will lookup an address for the host
itself, not the other way around.

Thanks to all that contributed, including:

Johnie Stafford,
"Scott D. Yelich" <>
Rich Pieri <>
"Schaffer, Gregory J." <>
"Mike D. Kail" <>
"James Ford" <>
Ronald Loftin <>
Tom Lojewski <> (Louis Hoo)
Aaron Dewell <>
"Auteria Wally Winzer Jr." <wally.winzer@ChampUSA.COM>



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