Comcast blocking email from our website domain...

[KeyserSoze]

My brother in law uses Telnap for his hosting, and Comcast periodically blocks his site from recieving mail from Comcast users, giving them the message: "450 [TEMPFAIL] destination not valid within DNS " - I've done all the normal troubleshooting I can think of. I don't know if they are blacklisting him, or what. He does NOT spam anyone. Normal person to person email communications.

It'll get blocked then work again, just randomly. Is there somewhere we can submit the domain to be reviewed?

I have contacted DeviousTrap (The owner of Telnap Hosting) but haven't heard back from him. If anyone has any places to send me to or things to try, I'm all ears. I've googled other users that have had the same problem, but not how they really fixed it.

TIA



KS

 

[RebateMonger]

The symptoms you describe don't necessarily point to any problems with Comcast. Rather, they point to problems on the Telnap side. While it IS possible for Comcast to block connections to your Brother-in-Law's email server, I'd expect a "550 (permanent)" error, rather than a "450 (temporary)" error.

If Comcast had a blocklist, it would normally block Comcast users from RECEIVING email from your brother-in-law's Telnap email server. But you said that HE can't receive email from Comcast.

First thing I'd do is take a look at your Brother-in-law's domain settings at:
http://dnsreport.com

If you see red warnings, you likely need to fix them. If the problem is sporadic, then try the same approach over a few days.

The message "450 [TEMPFAIL] destination not valid within DNS" looks like a problem with his DNS records.

Edit:
You can get a pretty good idea of the "Spam" status of your domain and your ISP by putting your Server's IP address in the "Spam Database Lookup" at http://dnsstuff.com. If your IP address is "listed" by any of the major Block Lists, then you have a problem.

 

[spyordie007]

This is probably a routing issue at Telnap. I ran into the same thing (Comcast users/servers not being about to hit the Telnap server addresses correctly).

I'd wait for a response from DeviousTrap, he's been quick to respond the times I needed him.

Erik

 

[lightpants]

I am having the exact same problem. I have a bunch of domains hosted at telnap and from time to time comcast users cannot email the users on those domains. It will work for a bit and then start failing again. I will also submit a trouble ticket to telnap and ask them to look into it.
Jim

 

[ITJunkie]

We had similar issue with comcast blocking email FROM us as spam (as RebateMonger pointed out). It was related to our multiple email domains and rDNS. Anyway, you can contact Comcast and make a request to be "unblocked" Here