Exchange Server database transaction logs record all changes to an Exchange Server database. Over time, these log files accumulate and use all the available disk space if they are not periodically removed from the hard disk.
Just a few words:
1. Dismount the Exchange Mailbox Database you wish to clean up.
2. eseutil /MH database.edb
If database are in a Clean Shutdown or Consistent state (Older ver), you may remove all the transaction logs (e000#*#.log).