mailcow share inbox or folder

Login to the sogo path on your mailcow server e.g. https://mailsrv.example.org/SOGo/
Click on the 3 dots next to the folder and choose Sharing…
Select the users mailbox and permissions.

Thunderbird: Make sure the user is subscribed to the new folder or it won't show up. Right-click on account in sidebar and choose Subscribe…

Tested on