I've come across some horror stories concerning this and wonder how they happen and if any one has done the import without any problems?

The reported problems seem to relate to indexing errors, speed -- really slow and multiple instances of the same email. Also CPU usage but I gained the impression that this user was also running desktop indexing - bad news for desktops with a lot in them.

I notice that the import for mail can be started on it's own. I have of course started up 12.3 Kmail with no emails in it so it's indexing will indicate this. Also seen mention of stopping the service, loading the mail and restarting it. Seems this is done in system settings - personal. All my 11.4 set up has there is the contacts files which I assume is the address book. I assume that on 12.3 it will also have something to do with emails there as well. As this "fixing" process seems to involve deleting it would be nice to know if it helps if things go wrong and a little more detail on what is going on and how best to do it. The comments were on the KDE forum and not explicitly resolved. The OP had spent 6 weeks trying.

The same post indicated that opensuse maintain a repo that allows a kde3.x email package that can be installed on 12.3. Anyone have any info on where and how etc?