We are facing one of our worst moments.
Due to internal server misconfiguration, we lost all received emails for the last 3 month. It's not affecting incoming, sent, draft or emails that were received before Feb 2016.
I'm trying to investigate the problem.
Update: After investigating, I found the error in a script, that did not remove the expiration index from records. This error caused received emails to prematurely expire. I most likely will be able to restore email up till April 3rd within next 24 hours, but unfortunately all emails from April 4 until May 23 are lost.
I want to apologize to everyone for the inconvenience, we will learn from this mistake and make sure it wont happen again.