David MacQuigg writes:
Forget about DKIM. What if there is some other reason to abort, like
the payload is too large?
RFC 1870 handles this special case, acceptably AFAICT.
The rest of general problem seems to be something most people choose to
live with rather than solve.
We cannot just continue receiving data forever. Is there a
"permissible" way within SMTP to abort during data, or should I just
ignore these ambiguous requirements, and either: 1) Send a TCP reset,
or 2) Let the transmitter hang.
Some people do this in order to be as occupy the sender's resources.
There's a fancy name for it. You send one byte every few minutes, so it
takes three hours to send the whole SMTP response. I don't know whether
doing so really inconveniences the $#(_at_)$#@! spammers and other evil
creatures who initiate most SMTP connections.