Would someone out there please take a stab at answering this question?
Or has it been answered already?
What to I mean by a 'mail source'? Well, in technical terms I'm thinking
someone could say something like:
"Here's info from a large ISP (handling mail for x million customers).
Over a period of ____ it accepted mail from x IP addresses that it
thinks were sending it mostly ham"
I'd be even happier with something like this:
it accepted mail from x TLD Names in the HELO.
I could live with something like: my greylisting server whitelisted x IP
addresses (I'm figure John Levine could give us this number quite
quickly for his a
"several hundred individual mailboxes, a few dozen mailing lists, and
the abuse.net message forwarding system.")
Of course, sometimes several servers send through one IP, or one server
sends through several IPs...
I'm guessing that there are under a million such mail sources. There
are around .1 billion TLD Names*.
This is apropos this thread: SPF Loses Mindshare at
http://www.circleid.com/article.php?id=1157_0_1_0_C/
*http://www.registrarstats.com/zonefile_enlarged.asp (Could be a few
times more more, as this doesn't list ccTLDs...)