We are having _really_ good results with SPFv1 so far.
2 months ago our e-mail was nearly unusable for the spam.
Fully 1/2 of our inbound e-mail has been SPF rejectable for the
past few days, with no detectable false positives (most of it I would
have manually filtered by subject or To:). Of the rest, about
10% have had SPF pass records, which are allowing me to be stricter
with my spam filtering.
My spam filters are hitting in the high 90%'s now, and my users have
not reported a false positive in 2 weeks.
SPF as it currently sits is incredible, and further deployment
of it will only improve matters. PLEASE, PLEASE, PLEASE be
careful about making changes to it now.
--
Daniel Taylor VP Operations Vocal Laboratories, Inc.
dtaylor(_at_)vocalabs(_dot_)com http://www.vocalabs.com/
(952)941-6580x203