On the subject of smtp enhanced status codes, am I correct in understanding
there is not currently a code for "mailbox does not accept binary messages"
a la 5.6.7 for SMTPUTF8?
At the time, I think the thought was that the sender would recode the
MIME parts as something less binary, base64 or qp, and try again.
Ned Freed's address is used as an example in the RFC so he may well
have more concrete observations.
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