Am Monday 14 March 2011 schrieb mir Benoit Panizzon:
We got two customers (one is another ISP) pretending that they have observed, that Google, Sunrise and other Services have startet flagging their customer's emails as spam, because the sender domain has not SPF record. Not an 'non matching' SPF record, but the sender just dones not use SPF at all.
From my point of view especialy an ISP should be very carefull with SPF.
Indeed. In my point of view, SPF is only useful in very special cases because the drawbacks are very wide spreaded and the benefit even small. Forcing SPF for cases where it doesn't fit is a very "interesting" step.
Using SPF in a spam filter to give some minor positive weighting in the spam score is ok but to use it to flag spam? I can't imagine that somebody does that. It sounds very stupid to me.
Regards Oli