I upgraded from current Yosemite to the El Capitan GM Candidate this morning. For work, I have an Exchange account with a bunch of folders in Apple Mail. Upon starting Mail after the upgrade, my folders were no longer present; Mail synced a few thousand messages, but it does not show the folders that are on the server.
I dug through the Exchange account preferences and the Mail preferences, but I haven't been able to find anything. Does anyone have a suggestion?