When I first set myself up with the mail add-on and configured the gmail POP I remember it taking a couple days to fully download all the mail.

After yesterdays Gmail blackout and the anticipation of the upcomming release I decided I would enable the email add-on for the rest of the users in our organization. 

Stuck on my first attempt, it seems as tho it grabbed about 200 emails this morning and has stopped. I have attempted to fetch several times since then and have left the window open.