Author: Murray S. Kucherawy Date: To: exim users Subject: Re: [exim] Rejecting messages with no "To:" or "Cc:" field inthe
headers
> -----Original Message----- > From: Murray S. Kucherawy
> Sent: Monday, February 28, 2011 6:08 PM
> To: exim users
> Subject: RE: [exim] Rejecting messages with no "To:" or "Cc:" field in the headers
>
> RFC2821 (2001) does a better job, but still not what you're looking
> for. It says the HELO parameter has to be the fully-qualified domain
> name of the sending machine. But it fails to define that as well; in
> particular, just because I don't have reverse DNS set up for my mail
> server doesn't mean its fully-qualified domain name isn't "foo.bar".
In fact, Section 4.1.4 of RFC2821 and of RFC5321 specifically disallow filtering based on a reverse DNS mismatch of the HELO/EHLO parameter.
