Rather than inserting our own home-grown header, everytime we save a
message to an IMAP server, we check if we suport the UIDPLUS extension
which provides us with an APPENDUID reply. Use that to find the new UID
if possible, but keep the old way if we don't have that extension.
If a folder is read-only, return the uid that we have passed in per API
description in folder.Base.py
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
3b8e1f91cd