Hello,
I don't understand anything about german, but maybe you'll find some
information here :
https://telekomhilft.telekom.de/t5/Andere-E-Mail-Programme/Evolution-mail/td-p/647215
You can also contact the project devs : https://wiki.gnome.org/Apps/Evolution
I've just changed my default mail application from evolution to icedove
(thunderbird fork), mainly because evolution doesn't displays correctly
multiple pop accounts, but I encçountered some other little problems. Maybe
you should give it a try.
