[Evolution] switching from KMail to Evolution

[matthias meyer gmx li]

I like to switch from KMail 5.9.3 to Evolution 3.30.5-1.1.

I've already installed Evolution in my Debian/KDE environment.
Unfortunately the menu "File/Import/data and configuration from old programs" 
informs me that he was looking for data for Pine, Netscape,iCalendar and KMail 
but nothing found.
I'm very sure to have ~5GB Mails in maildir format in $HOME/KMail/.

How I can import my mails into evolution?

Thanks in advance
AthLux