John C Klensin wrote:
Is this on topic, important? a non-issue?
Mostly a non-issue, I think.
The problem of "empty mails" as the result of DATA<CRLF>.<CRLF>
is unfortunately a permanent issue in "mail abuse" news groups.
Some "missing" header fields like Date / From / To created by
the MDA are not what most users want.
The delivery MTA may look (although it doesn't have to), but
there is a strong case to be made that, if it doesn't like
what it receives, it should bounce the message rather than
trying to fix it up
Yes, that could be better, at least if it's also the MX, or if
the envelope passed some tests before. Otherwise sending
bounces to (most probably) innocent bystanders would be a waste
of bandwidth, then it's cheaper to dump this garbage in the
mailbox of a local user. Maybe adding "Subject: sorry", if all
header fields are fictitious then a bogus subject isn't worse.
It can't be a SEND FROM if it's a MAIL FROM. If an instant
messaging protocol uses SEND FROM to transport empty messages,
then that special case should be obvious.
Bye, Frank