Re: Received header field for special processing, such as "held for moderation".
Dave CROCKER wrote:
Occasionally, the Other Crocker ventures into email space and he chose
to be more thoughtful about a brief thread that was just on the IETF
listthat noted a message delay due to being held for moderation.
Currently, nothing in the message (or smtp responses, of course)
signals this reason for delay. (For those who haven't seen the
thread, the person initiating the the thread thought the delay was due
to DKIM processing...
It would be quite simple to add a Received header field, when a
message is placed into a moderation queue, noting that fact.
What problem you're trying to address? A mechanism to report any
arbitrary delay, or are you specifically thinking about moderator delays
on a list?
Mail filtering products have all kinds of reasons they may choose to
deliberately hold a message, e.g., a message that appears to contain
restricted content might be approved for sending outside the corporate
walled garden; a virus filter may have flagged a message as "suspicious"
and taken it "offline" for a more time-consuming examination, like
sand-boxing; a delay caused by a referral (4xx response).