Have you tried just using the Icedove profile from within
I've just installed Debian 9 (stretch) and I'm trying
to import folder with messages from Icedove
38.5.0 at my old PC (running debian 8) to
my new PC with Thunderbird 52.8.0.
In Icedove I select a folder and Tools -> Import/export in
mbox/eml format -> Export folder
And save the file in a pendrive.
Thunderbird I select Tools -> Import -> Messages ->
Mail -> Next
only the message: No application or data file to import
option to select the file that contains the
contact list as in