Osiris wrote:

Ah, yes , obviously, but that did not work. It stubbornly stayed
greyed-out
I found out, I had to rename the stubborn outlook.pst, start a new,
empty .pst file, put the empty contact list in the address book (by
the previously grayed-out mark) and then import the renamed file's
content into the empty .pst.

That should not have been necessary. If you add the OAB service correctly,
it will work.
--
Brian Tillman