Exchange Server 2010 SP1 (Enterprise) In the past 36 hours my mailbox DB went from a little under 200GB to almost 450GB, and for the life of me I cannot figure out why. We are a relatively small company, and nothing has changed on the Exchange Server recently in any way. I don't see any problems in the event logs, and using TreeSize I can see that the Mailbox Database file is taking up all the space. How can I start to figure out what caused this? What are some things I can do to clean this up? I have very little experience troubleshooting Exchange problems such as this so any assistance is greatly appreciated.

Please check database file size and the log file size, also let know about your exchange server backup practise.