RDNS failed in email full header

  • Thread starter Thread starter Roy Avery
  • Start date Start date
R

Roy Avery

Why do our incoming email messages have a "RDNS failed" in the header? What can I do to fix this?


---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from senderdomain ([senderIPaddress] RDNS failed) by emailservername with Microsoft
SMTPSVC(5.0.2195.6713);


Thank you.

Roy Avery
 
It means that the mail server tried to do a reverse DNS lookup on the IP
address and there was no PTR record published. For mail servers it is
important that you publish a reverse entry that matches the forward A record
you have published in your zone. Please read RFC 2505 and then RFC 2317.

You can also review my PowerPoint slide deck at:
http://www.sfntug.org/index.php?option=com_weblinks&task=view&Itemid=4&catid=87&id=22
if you want more details about what folks are doing as anti-spam techniques.

So, in a nutshell, publish a Pointer Record (PTR) in the reverse file and
you should be good to go.

Regards,
Ed Horley
Microsoft MVP Server-Networking
 
Thanks Ed.

I'll check out the presentation right away. I have a quick question though, did the RDNS fail
against the sender's IP because the recipient did not have a PTR record, or because the sender did
not have a PTR record?

---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from sender_domain ([sender_IPaddress] RDNS failed) by
recipient_email_servername with Microsoft SMTPSVC(5.0.2195.6713);



Ed Horley said:
It means that the mail server tried to do a reverse DNS lookup on the IP address and there was no
PTR record published. For mail servers it is important that you publish a reverse entry that
matches the forward A record you have published in your zone. Please read RFC 2505 and then RFC
2317.

You can also review my PowerPoint slide deck at:
http://www.sfntug.org/index.php?option=com_weblinks&task=view&Itemid=4&catid=87&id=22
if you want more details about what folks are doing as anti-spam techniques.

So, in a nutshell, publish a Pointer Record (PTR) in the reverse file and you should be good to
go.

Regards,
Ed Horley
Microsoft MVP Server-Networking


Roy Avery said:
Why do our incoming email messages have a "RDNS failed" in the header? What can I do to fix this?


---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from senderdomain ([senderIPaddress] RDNS failed) by emailservername with Microsoft
SMTPSVC(5.0.2195.6713);


Thank you.

Roy Avery
Click to expand...
Click to expand...
 
It looks like it was because the sender did not have a PTR record.

Regardless, you should make sure you have your set up! It will help you
avoid issues long terms with sending and receiving e-mail from your MTA in
the future.

Regards,
Ed Horley
Microsoft MVP Server-Networking

Roy Avery said:
Thanks Ed.

I'll check out the presentation right away. I have a quick question
though, did the RDNS fail against the sender's IP because the recipient
did not have a PTR record, or because the sender did not have a PTR
record?

---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from sender_domain ([sender_IPaddress] RDNS failed) by
recipient_email_servername with Microsoft SMTPSVC(5.0.2195.6713);



Ed Horley said:
It means that the mail server tried to do a reverse DNS lookup on the IP
address and there was no PTR record published. For mail servers it is
important that you publish a reverse entry that matches the forward A
record you have published in your zone. Please read RFC 2505 and then
RFC 2317.

You can also review my PowerPoint slide deck at:
http://www.sfntug.org/index.php?option=com_weblinks&task=view&Itemid=4&catid=87&id=22
if you want more details about what folks are doing as anti-spam
techniques.

So, in a nutshell, publish a Pointer Record (PTR) in the reverse file and
you should be good to go.

Regards,
Ed Horley
Microsoft MVP Server-Networking


Roy Avery said:
Why do our incoming email messages have a "RDNS failed" in the header?
What can I do to fix this?


---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from senderdomain ([senderIPaddress] RDNS failed) by
emailservername with Microsoft SMTPSVC(5.0.2195.6713);


Thank you.

Roy Avery
Click to expand...
Click to expand...
Click to expand...
 
Thank you very much.




Ed Horley said:
It looks like it was because the sender did not have a PTR record.

Regardless, you should make sure you have your set up! It will help you avoid issues long terms
with sending and receiving e-mail from your MTA in the future.

Regards,
Ed Horley
Microsoft MVP Server-Networking

Roy Avery said:
Thanks Ed.

I'll check out the presentation right away. I have a quick question though, did the RDNS fail
against the sender's IP because the recipient did not have a PTR record, or because the sender
did not have a PTR record?

---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from sender_domain ([sender_IPaddress] RDNS failed) by
recipient_email_servername with Microsoft SMTPSVC(5.0.2195.6713);



Ed Horley said:
It means that the mail server tried to do a reverse DNS lookup on the IP address and there was
no PTR record published. For mail servers it is important that you publish a reverse entry that
matches the forward A record you have published in your zone. Please read RFC 2505 and then RFC
2317.

You can also review my PowerPoint slide deck at:
http://www.sfntug.org/index.php?option=com_weblinks&task=view&Itemid=4&catid=87&id=22
if you want more details about what folks are doing as anti-spam techniques.

So, in a nutshell, publish a Pointer Record (PTR) in the reverse file and you should be good to
go.

Regards,
Ed Horley
Microsoft MVP Server-Networking


Why do our incoming email messages have a "RDNS failed" in the header? What can I do to fix
this?


---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from senderdomain ([senderIPaddress] RDNS failed) by emailservername with Microsoft
SMTPSVC(5.0.2195.6713);


Thank you.

Roy Avery
Click to expand...
Click to expand...
Click to expand...
 
If you have Trend IMSS with SPS with reverse lookup checking configured. It
inserts "RDNS Failed" into the header.

Cheers
Simon
---
Roy Avery said:
Thank you very much.




Ed Horley said:
It looks like it was because the sender did not have a PTR record.

Regardless, you should make sure you have your set up! It will help you
avoid issues long terms with sending and receiving e-mail from your MTA
in the future.

Regards,
Ed Horley
Microsoft MVP Server-Networking

Roy Avery said:
Thanks Ed.

I'll check out the presentation right away. I have a quick question
though, did the RDNS fail against the sender's IP because the recipient
did not have a PTR record, or because the sender did not have a PTR
record?

---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from sender_domain ([sender_IPaddress] RDNS failed) by
recipient_email_servername with Microsoft SMTPSVC(5.0.2195.6713);



It means that the mail server tried to do a reverse DNS lookup on the
IP address and there was no PTR record published. For mail servers it
is important that you publish a reverse entry that matches the forward
A record you have published in your zone. Please read RFC 2505 and
then RFC 2317.

You can also review my PowerPoint slide deck at:
http://www.sfntug.org/index.php?option=com_weblinks&task=view&Itemid=4&catid=87&id=22
if you want more details about what folks are doing as anti-spam
techniques.

So, in a nutshell, publish a Pointer Record (PTR) in the reverse file
and you should be good to go.

Regards,
Ed Horley
Microsoft MVP Server-Networking


Why do our incoming email messages have a "RDNS failed" in the header?
What can I do to fix this?


---------example-------------
Microsoft Mail Internet Headers Version 2.0
Received: from senderdomain ([senderIPaddress] RDNS failed) by
emailservername with Microsoft SMTPSVC(5.0.2195.6713);


Thank you.

Roy Avery
Click to expand...
Click to expand...
Click to expand...
 
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