Sharing Tasks Over DAV Workaround

I've tested this on Evolution (Linux) and DAVx⁵ (Android). Whenever you share a Tasks folder with your own Team member, it won't show up in their DAV list no matter what setting they try to adjust on the mailbox.org side. In order for them to access it with their DAV client, they will need help from the person that originally created it.

The person that created it needs to have their own DAV client. I'll use DAVx⁵ in this example:

If you haven't already, install DAVx⁵ (https://www.davx5.com/) and sign in with your mailbox.org account.

Go to CALDAV for your account and tap the menu to the right of the Tasks folder you're trying to share.

Select Properties.

There you will find the URL of the Tasks folder (should be something like https://dav.mailbox.org/caldav/XXXX/ with the XXXX being the unique string for your folder)

Now that person needs to share that URL with the other users trying to access it. The rest of the instructions are for the users trying to access the shared Tasks:

If you haven't already, install DAVx⁵ (https://www.davx5.com/) and sign in with your mailbox.org account.

Now, add another account with the + icon at the bottom right of the main screen.

Select "Login with URL and user name".

Enter the URL shared to you by original user (https://dav.mailbox.org/caldav/XXXX/) along with your mailbox.org User name and password.

When selecting what the subscribe to in the new DAVx⁵, only subscribe to the shared Tasks folder. Everything else you should subscribe to in your main account on DAVx⁵ to prevent conflicts.

Now you're good to go! Evolution can also directly subscribe using the same URL and credentials