[ietf-dkim] SPF, was forward to friend...

[Alessandro Vesely]

Ian Eiloart wrote:
> Actually, I'm finding SPF quite useful. Rejecting spf fails, spam scoring 
> on softfails, and limiting the exposure caused by whitelisting.

+1, whitelisting based on SPF or DKIM seems to work well for most 
lists that transmit invalid "From" values (besides ADSP, it is quite 
frequent to get, e.g., joe at NOSPAM.example.org.)

One question is whether SPF is a good method for selecting the 
/second party signature/, for reputation checking, in case there is 
no valid author domain's signature, but multiple valid signatures 
are present. In facts, servers that run various virtual domains on 
the same IPs cannot use rDNS to tell on behalf of which domain the 
current transmission is meant to be.