said by yvovandoorn 
:i can confirm that this is also happening with email to speakeasy.
Reporting-MTA: dns; comcast.net
Arrival-Date: 19 Oct 2005 17:46:23 +0000
Final-Recipient: rfc822;
Action: failed
Status: 5.1.0 MAIL FROM: 553 REPLY: 553_sorry,_your_mail_from_a_host_[63.240.77.84]_without_valid_reverse_DNS_was_administratively_denied_(#5.7.1)
Diagnostic-Code: smtp; Permanent Failure: Other address status
Last-Attempt-Date: Wed, 19 Oct 2005 17:48:21 -0000
or to a Speakeasy hosted website:
Reporting-MTA: dns; comcast.net
Arrival-Date: 19 Oct 2005 17:38:49 +0000
Final-Recipient: rfc822;
Action: failed
Status: 5.1.0 MAIL FROM: 553 REPLY: 553_sorry,_your_mail_from_a_host_[63.240.77.81]_without_valid_reverse_DNS_was_administratively_denied_(#5.7.1)
Diagnostic-Code: smtp; Permanent Failure: Other address status
Last-Attempt-Date: Wed, 19 Oct 2005 17:40:48 -0000
Using mail.app on a Mac or Entourage...
This speakeasy issue is different than the hotmail 550 problem -- probably.Reverse DNS for 63.240.77.81
Generated by www.DNSstuff.com
Location: United States [City: San Diego, California]
Preparation:
The reverse DNS entry for an IP is found by reversing the IP, adding it to "in-addr.arpa", and looking up the PTR record.
So, the reverse DNS entry for 63.240.77.81 is found by looking up the PTR record for
81.77.240.63.in-addr.arpa.
All DNS requests start by asking the root servers, and they let us know what to do next.
See How Reverse DNS Lookups Work for more information.
How I am searching:
Asking h.root-servers.net for 81.77.240.63.in-addr.arpa PTR record:
h.root-servers.net says to go to epazote.arin.net. (zone: 63.in-addr.arpa.)
Asking epazote.arin.net. for 81.77.240.63.in-addr.arpa PTR record:
epazote.arin.net [192.41.162.32] says to go to CBRU.BR.NS.ELS-GMS.ATT.NET. (zone: 240.63.in-addr.arpa.)
Asking CBRU.BR.NS.ELS-GMS.ATT.NET. for 81.77.240.63.in-addr.arpa PTR record:
cbru.br.ns.els-gms.att.net [199.191.128.105] says to go to ns1.itv.att.net. (zone: 77.240.63.in-addr.arpa.)
Asking ns1.itv.att.net. for 81.77.240.63.in-addr.arpa PTR record: Reports sccrmhc11.comcast.net. [from 204.127.193.29]
Answer:
63.240.77.81 PTR record: sccrmhc11.comcast.net. [TTL 10800s] [A=63.240.76.21, 63.240.77.81, 204.127.202.55]
To see the reverse DNS traversal, to make sure that all DNS servers are reporting the correct results, you can Click Here.
·
·