Thanks for following-up, Bill.

While I fully understand the need for unit-testing, I don't have the
guts to start writing a dummy imap server from scratch.

I tested my changes on a couple of servers I manage, one running
uw-imapd and the other running cyrus imapd; still, I don't think unit
tests could rely on a "real" server. On the other hand, I don't think a
python.org hosted test server would be a very wise choice: even if we
found some dummy all-data-in-memory server, I fear the ssl/tls load on
the server.