Bounced e-mails due to reverse DNS no active?

[superjet]

Hello,
I have an Exchange 5.5 server on Win2K server that has been cooking along just fine.
In the last month, I have had a few users tell me they have not been able to receive e-mails from some of our customers. The consensus is our reverse DNS is not working on our e-mail server.

Anyone out there be able to help a brother out? I have no clue where to start.
Is it here? Is it my ISP?

Thanks in advance,
Jamie

 

[cmeagan656]

I would thing that if you can't receive emails that it is because your mail server requires a reverse DNS from the sending server(s) and the sending server(s) do not have one. It is the senders' problem, not yours.

If your reverse DNS was not working you would not be able to send emails to those servers requiring a reverse DNS not the other way around.

Cheers.

 

[superjet]

Thanks for the reply, but I got it backwards.
People are having trouble SENDING us e-mails. I was rushed when I wrote the post.

Sorry.

 

[rdroske]

Right and you wouyld have to have an add-on. Exchange 5.5 doesn't have an option to make it do reverse DNS verification built in (as far as I know anyways).

But I'm a little confused now. You said you got it backwards in the first post but then you said the same thing. People are having problems sending emails INTO your Exchange server. (your users having trouble receiving in the first and outside users having trouble sending in the second?)

So if thats it, unless you have something running in front of your Exchange it wouldn't seem to be a reverse DNS issue for either party.

The people having trouble sending should be getting some kind of NDR though?

 

[cmeagan656]

If you do have a DNS issue you can check your reverse DNS here:

http://remote.12dt.com/rns/.

You could also check this out:

http://www.dnsstuff.com/.

I agree with rdroske though. The place to start troubleshooting is is with the NDR. Try to get hold of an NDR from a problem sender and post it here for us to have a look at.

Cheers.