Multiple PTR records

[Chris Buxton]

On Jan 16, 2009, at 7:13 AM, Matus UHLAR - fantomas wrote:
> Actually, it doesn't matter which PTR record will remain, unless  
> there will
> be any SPF record pointing to it.

That is a common misconception. 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.

The SMTP greeting name should also have an A record that resolves back  
to the address used as the source address of the connection. I once  
saw an SMTP server used to send mail from several unrelated domains,  
where each one was sent out through a different address. The mail  
server used the same name in the SMTP greeting regardless of which  
domain it was sending for, and this caused problems for all of the  
other domains.

Chris Buxton
Professional Services
Men & Mice