mx record ?

[Stephen Reese]

When recieving mail from a source suchas paypal i've noticed the following:

Received: from smtp1.nix.paypal.com (smtp1.nix.paypal.com
[::ffff:64.4.240.74])
  by prcdigital.com with esmtp; Mon, 13 Sep 2004 20:37:10 -0400

but when someone recieves an email from us:

Received: from prcdigital.com (mail.prcdigital.com [::ffff:66.35.133.90])
     (TLS: TLSv1/SSLv3,168bits,DES-CBC3-SHA)
     by ns.neocipher.net with esmtp; Tue, 14 Sep 2004 16:01:46 -0400

or

Received: from mail.prcdigital.com (localhost [::ffff:127.0.0.1])
     by prcdigital.com with esmtp; Tue, 14 Sep 2004 16:58:15 -0400

The only difference is one was sent out using outlook and the other using
webmail. The issue that is really bothering me is the ns.neocipher.net and
then in the second one the localhost part. Am I even correct that this is
a dns issue?

The following is our zone file for prcdigital.com:

$TTL 3h
@               IN SOA ns1.prcdigital.com. sreese.prcdigital.com. (
                        1       ; serial
                        3h      ; refresh
                        1h      ; retry
                        1w      ;expire
                        1h )    ; minimum

                NS      ns1.prcdigital.com.
                NS      ns2.prcdigital.com.

                MX      10 mail.prcdigital.com.

                A       66.35.133.90
localhost       A       127.0.0.1
mail            A       66.35.133.90
ns1             A       66.35.133.90
90              PTR     ns1
ns2             A       66.35.133.91
91              PTR     ns2
www             A       66.35.133.90
ftp             A       66.35.133.90

Does this look correct?