Glenn Anderson wrote:
At 6:12 pm -0500 29/11/2007, Hector Santos wrote:
So 421 is implied for real server critical shut down reasons in 2821
compliant servers across the board.
However shutting down because it doesn't like a parameter on a NOOP
command is to me a very clear violation of section 3.9 of RFC 2821
(section 3.8 in 2821bis):
In particular, a server that closes connections in response to
commands that are not understood is in violation of this
+1, I agree.
The question is, why did it happen? was the specs ambiguous? Was it a
legacy 821 system which does not have an string for NOOP who had to
decide between 500 and 421, both wrong, but nonetheless used in a major
vendor product line, and possibly others? Was it a proxy and this major
vendor had nothing to do with it?
Whatever the reason, maybe 2821bis can help minimize NOOP issues in
future SMTP servers and also help legacy developers or proxy writers
fine tune their own products.
Thanks for your comments.