Re: [Exim] Trying to compare HELO data with actual host info…

> The following type of thing happens all the time
> Received: from 209-187-167-231.hsacorp.net ([209.187.167.231]
>     helo=hotmail.com)
> I would like to compare the actual rDNS data with the HELO info in the
> specific case of hotmail.

|      5.2.5  HELO Command: RFC-821 Section 3.5
| 
|         The sender-SMTP MUST ensure that the <domain> parameter in a
|         HELO command is a valid principal host domain name for the
|         client host.  As a result, the receiver-SMTP will not have to
|         perform MX resolution on this name in order to validate the
|         HELO parameter.

|         The HELO receiver MAY verify that the HELO parameter really
|         corresponds to the IP address of the sender.  However, the
|         receiver MUST NOT refuse to accept a message, even if the
|         sender's HELO command fails verification.