I have to say, in the 7 months or so since I got into this whole linux webserver, this is the most active thread I have ever encountered. I would assume most of us are a little unsure about the whole dkim/spf/sender id thing. And even according to the websites themselves, they are not sure of their own standards. I think it would be safe to assume you need to program/configure for the mass email systems like gmail, yahoo, hotmail, aol, etc....and assume (quite rightly) that everyone else will not have any problems with your mail at all. So I think anything done to the mail config at this point is just to make yahoo happy. Oh, cause nothing I like more than to make yahoo happy. Ask their shareholders is yahoo makes them happy...lol