Hvis det
er en imap konto, så tror jeg kun det kan lade sig gøre med et husmandstrick eller Work around, som bl.a. beskrevet her:
https://www.techrepublic.com/article/reclaim-outlook-categories-for-imap-accounts/Citat
Fortunately, you don't have to convert your IMAP account to a POP3 account to reclaim categories; you can use shortcuts assigned to the categories. To see these shortcuts, open a new message (click New Email in the New group on the Home tab or press [Ctrl]+N). Then, click the Tags dialog launcher. In the resulting dialog, choose All Categories from the Categories dropdown. Outlook will list the default categories (Figure C). If there aren't any, just use the New option to create them. At this point, you can check a category to assign it to the new email message. After assigning one category to an existing message, you can right-click it in the message window to assign others. It's a lot of work, but shortcuts eliminate most of those steps.(Hvis din konto - også? - er en imap konto og du
har kategorivælger-knappen, så er det mystisk.)