It appears your real disagreement is with the IMAP mailbox abstraction with its guarantee that messages won't randomly disappear beneath a client.If there is indeed such a guarantee, then I have two problems with it: it's too cumbersome, and it isn't clearly stated in RFC3501.
There is such a guarantee.
It is not at all cumbersome to clients. They love it.
It was not too cumbersome to the multiple existing servers (including the very first servers) that have implemented it.
Finally, RFC 3501 has the text about msg-att-static which effectively does state this guarantee. Message texts are included in msg-att-static.
-- Mark --
http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. Si vis pacem, para bellum.
