Running GW8HP1 on NW65SP8, mind you I've seen this problem for quite some
time going back several versions...

Once in a while I get an email from the GWIA with subject "Undeliverable
gateway message", and in the message is part of an email with various MIME
encoding and so on. In some cases it looks like the email address was
messed up, in some cases I don't see any problem but I'm not a MIME expert.

If memory serves this is caused by some MIME encoding error from the sending

However what I'm wondering about, is if the GWIA has a problem processing an
inbound message, why is it accepting it at all? It should reject it, so
that the sender knows their message didn't get through and to resend it. By
accepting it partially and then bouncing me (the postmaster) an
undeliverable with only part of the message (and a MIME encoding of any
attachments) all I can do is tell the person internally that this person was
sending you a message and here's part or none of it and ask them to resend.
On top of it if I'm not in front of a computer (for instance on my
Blackberry) I won't be even able to tell them this until the next time I
have computer access, in the meantime as far as the sender is concerned they
sent the email, our email system accepted it, and it's our fault or cost if
something isn't done according to their instructions.

Is there a setting somewhere where I can tell the GWIA to just reject
anything that can't be 100% processed into the users' mailbox?