Multiple PTR records

[sthaug at nethelp.no]

> > I have seen mail bounced because of a  
> > mismatch between SMTP greeting name and PTR record name. It's not as  
> > common as the simple "is there any PTR record" check, but it does  
> > happen.
> 
> - it's clear violation of RFC 5321 (and former 2821, 821) - server MUST NOT
>   reject connection because of that. 

In today's spam-filled environment, a "MUST NOT" from RFC 5321 probably
rates considerably lower than reducing the total amount of spam. So
*if* a postmaster finds out that rejecting mail due to such a mismatch
indeed reduces the spam level for his users - he'll probably do it. He
may not even have any idea what the RFC says...

All I'm saying is - don't expect the RFCs to have the force of law.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no