Mail Inbox Sub-folder doesn't show up
I have a 1and1 account set up in the mail app (El Capitan) with SMTP. I recently tried to set up a rule that sends certain emails into a subfolder. Through 1and1's web interface I can see the sub-folder and its corresponding email. However, in the mail app it's not there. If I go to "show account info" it's listed, but trying to view the messages through that brings up nothing. I thought they'd both be in sync. Do I need to manually add this folder in the mail app?
OS X El Capitan (10.11.1)