I have both IMAP folders (from a Kolab install) and local maildir folders set up in KMail. When I set the default sending identity in the propertie dialog on the top-level node of the IMAP tree (labelled "imap.mykolab.com") and press "OK", the entire IMAP folder tree disappears. If I check email, some folders re-appear. If I restart Kontact, all the folders are back. The sending identity setting does not stick, however. Setting this on actual folders works. Setting it via the account settings also works. Reproducible: Always
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.