I run kmail without a desktop environment. (I use fvwm2 for my window manager, but no KDE/Gnome/xfce/etc.) I just upgraded from kmail 1.13.7 (under KDE 4.8.4) to kmail 5.9.3 (under KDE Frameworks 5.54.0).

When I ran kmail after upgrading, nothing migrated: no emails, no folders, no customization (colors, toolbars, shortcuts), no toolkit/UI customization (menu colors and fonts). It's just like I ran a completely fresh install, having never run kmail ever before. Except it did keep my "Identities" and "Outgoing Accounts" -- bizarre.

Anyway is there a way to migrate any or all of my configuration and data? (In my old kmail 1.13.7 there was no menu item for exporting, such as "Tools < Import/Export KMail Data".) I am interested in:

kmail data (emails and folders) well, that's probably for a different forum
kmail configuration and customization
KDE customization that affects the look of kmail

Thanks.