Hi
> The intent is to determine experimentally, the 'real', not
> theoretical, response of a submitting client [1], if/as/when
> the server with which it has estabished a connection were to
> issue a 'RSET'. More accurately, an unexpected RSET.
A server cannot send and RSET command, as commands are by definition only
sent by the client.
If a server were to send "RSET" CRLF, the client would need to try to
interpret this an an response to the last sent command. But as it is NOT
starting with a code number, it will fail.
The sequence "RSET" CRLF may however even legally be sent by an smtp server,
for example as part of something like:
"250 accepted. id=SOMENICEISFORUSERSET" CRLF
Notice however that this is no command, as commands are ONLY sent by the
client at the beginning of a line (and outside a message body).