After further deliberation about source routing and SPF, I have come
around to the conclusion that Frank is to some degree right, and if
you want to use SPF/Sender-ID, you should use source routes.
Source routes require all mail servers to be open relays.
Only in a naive implementation. SPF already requires that participating
hosts be prepared to handle arbitrarily complex procedures, so adding one
more shouldn't be a big deal. If it is a big deal, well, perhaps we're
seeing a problem with SPF more than with source routes.
Regards,
John Levine, johnl(_at_)iecc(_dot_)com, Primary Perpetrator of "The Internet
for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Mayor
"I dropped the toothpaste", said Tom, crestfallenly.