On Friday, September 03, 2004 at 9:46 AM, Arnt Gulbrandsen wrote:
What happens if a message is sent on Saturday, the sender publishes a
new policy on Sunday, and the recipient's MUA attempts to verify the
message on Monday?
If I recall correctly, in the original CallerID spec:
1. If you're retiring use of an MTA, your record should continue
to reference it for at least 28 days after it last sent outgoing
mail. and
2. An MUA must not attempt to validate messages received by their
org more than 28 days ago.
-- Jim Lyon