451 4.1.8 Possibly forged hostname

[wpwood3]

There is one ISP that is rejecting mail from my mail server with the following error:

 
451 4.1.8 Possibly forged hostname for 205.209.51.116

My domain is mercedesshop.com.

Is there a problem with my mail server or is the issue with that ISP?

This is the definition I found for error 451 4.1.8:
"This means that it was able to resolve the IP address, but it doesn't resolve to a hostname that matches both forward and reverse lookups."

Please note that all of my incoming mail is routed through a proxy mail server to filter spam and viruses. I would not think that would make any difference for SMTP.

[wpwood3]

Since my servername is mbshop2.mercedesshop.com
Would it help if I added an A record for mbshop2?

I am not using mbshop2 as a hostname for any of my webs.

[wpwood3]

Originally Posted by wpwood3

Since my servername is mbshop2.mercedesshop.com
Would it help if I added an A record for mbshop2?

I'm going to try adding the A record for mbshop2 and see if it fixes the problem.

[wpwood3]

Adding an A record for mbshop2 seems to have fixed the problem with the one ISP that was refusing email from my server.

Now on to the next problem...
I have another customer who is not getting emails from us. This one has a US Army email address. Whenever my mail server sends to him the connection times out. This one may be tougher to solve because there's no error code.

[falko]

Please check if your server got blacklisted: http://www.mxtoolbox.com/blacklists.aspx