> Well, yes, but it depends on whether this means immediately
> after DATA, or after the final "." at the end of the content.
> It would be unusual for a server to respond 2yz for at least
> one RCPT and then immediately respond 4yz or 5yz (rather than
> 354) to DATA; my interpretation of John's statement was that a
> server which did so was out of scope for the part of the spec
> under discussion.
Unless it did so as one of the "shutting down service" or
equivalent messages. I.e., 450 might make sense, other 4yz or
5yz codes would be very unusual.
452 insufficient reousrce sorts of codes are also a possbibility here.
Of course, if there were no
valid recipients, even "command out of sequence" (or equivalent)
would be plausible.
Other permanent failures are also possible, e.g., various things along
the lines of "Something you have said caused me to hate you and I'm rejecting
this tranaction in toto".
Ned