I installed the Mailbox plugin for the shelf but I don’t know how to get it to work. Help!
Did you add it to your shelf? You might have to hit Browse when you go to add it the first time.
Yes, I had to hit browse. I just got it working.
if I add it, it first works for the first period, but then it shows me an error 
but that add-in is not very important for me 