Question : Exact match needed with Reverse DNS?

Hi all,

All e-mail from my company shows up as [email protected].  My reverse DNS entry is listed as mail2.domain.com.  This has worked for us, and we have no problems sending mail to the usual suspects:  AOL, Yahoo, Hotmail, etc.

Earlier this week, I sent an e-mail to a small company, and my message bounced:



I changed my Exchange settings so my address showed up as [email protected] (added the mail2 part), and the message was delivered fine.  However, I'd rather not keep that setting.

Does my reverse DNS need to match exactly (i.e. point to domain.com instead of mail2.domain.com) or is this company just being overly aggressive?

Also, if I change the reverse DNS to just be domain.com, will that cause any other problems?  Our web site domain.com is hosted externally, and so the A record for domain.com will not match the address where the mail is originating from.  Does anyone do that kind of verification?

Thanks for any help.
Eric

Answer : Exact match needed with Reverse DNS?

Is your HELO sending the same name as your PC and MX record? If not, then yes you need to make sure it does. I think the mail servers that check for these things check both IP address and the HELO name.