Why SPF over PTR?

[David Botham]

bind-users-bounce at isc.org wrote on 11/29/2004 03:12:27 PM:
> I must not be understanding SPF correctly because I don't understand
> why it is better for preventing sender domain forgeries than doing a
> simple PTR lookup.
> 
> Wouldn't a simple comparison of the sender's IP address to their
> domain name via a PTR record lookup be sufficient to check for
> forgeries? I realize that not everyone has PTR records, but more have
> PTR records than SPF records.
> 
> What am I missing?

A PTR RR simply says that a given IP points to a certain host name.  SPF 
says which hosts may source mail on a domain by domain basis. 


Dave...

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