Somehow during the clean up for the drive that hosts the mailbox.edb file, it became compressed. I've tried using the command line- compact /u /s command to decompress it as well as going into the advanced properties and unchecking 'Compress contents to save disk space' on the file- however neither techniques not seem to apply or remove the compression attribute. The file is still blue and has a 'C' in the attribute column. If i open the advance attributes the check is back in the box. I've rebooted and attempted these two techniques a few times without success.
MSExchangeIS (2536) First Storage Group: An attempt to open the compressed file "D:\Mailboxes\Mailbox Database.edb" for read / write access failed because it could not be converted to a normal file. The open file operation will fail with error -4005 (0xfffff05b). To prevent this error in the future you can manually decompress the file and change the compression state of the containing folder to uncompressed. Writing to this file when it is compressed is not supported.
Obviously all users are unable to connect to the exchange server to send/receive email.