When to acknowledge messages for per-recipient data reply / deferred rcp

After reading many archived messages on per-recipient data reply / 
deferred rcpt reply I have come up with a thought regarding when to 
acknowledge recipients / messages.
I think that (valid) recipients should be acknowledged as soon as 
(reasonably) possible.  I'm thinking about the number of sending systems 
that I've had to deal with that have had failed connections part way 
through transmission of messages.  If a recipient is acknowledged as 
soon as (reasonably) possible rather than waiting until all recipients 
have been processed it is more likely that sending systems will receive 
the acknowledgment prior to failed transmission, thus having fewer 
recipients that it needs to re-send the message for.  The only reason 
that I can come up with as to why not do this is for a performance / 
efficiency reason(s) out weighing the desire to have a robust protocol 
that will still partially work for some recipients in the event of a 
communications failure.


Grant. . . .