trying to figure out why mail is bouncing

[bscott at ntisys.com]

On Fri, 31 Oct 2003, at 9:19am, jfreeman at threeofus.com wrote:
>> When I did a lookup on the IP address, I got an NXDOMAIN error. There is
>> apparently no reversae lookup for your mail server.
>
> would someone kindly let me know what changes I need to make to my host
> file in order to fix this?

  The /etc/hosts file has nothing to do with it.  You need to have your ISP
put a PTR (pointer) entry in the DNS for your IP address.  Or have them
delegate your IP subnet to DNS nameservers you control.

  Hmmm, I notice that the MX for the domain <threeofus.com> is
<mail.threeofus.com>, and that <mail.threeofus.com> is a CNAME for
<threeofus.com>.  Per the RFCs, the right-hand side of an MX record can only
be the canonical name.  That can cause trouble, too.

  Anyhows, I see you have IP address <199.232.38.4>.  That reverses to
<4.38.232.199.in-addr.arpa.>.  Following the delegation chain from the
roots, I see your ISP says <4.38.232.199.in-addr.arpa.> is a CNAME for
<4.threeofus.com.>.  If you put a PTR record in for that name with RHS
<threeofus.com>, that should fix things up.  That, and fixing
<mail.threeofus.com> to have an A record, rather then a CNAME.

-- 
Ben Scott <bscott at ntisys.com>
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