On Wed, 2008-07-23 at 08:16 -0400, Keith Moore wrote:
"MUAs, Message Stores, and MTAs, MUST NOT delete a message on the basis
of an Expired header field unless given explicit instructions to do so
by the recipient."
I find it very desirable to have MTAs generate a bounce if the message
is older than the Expired header.
I do not. The problem with trying to do this at the MTA level is that the
preferences of the recipient cannot be properly taken into account.
If you want this sort of service at the transport level, use the DELIVERBY
extension, not an Expired: header. This is what it is for. IMO Expired: should
only be used as an MUA-level facility.