Yes, MessageStats contains reports called Content Analysis - Attachment Count by Size or Mailbox Content - Audit Item by Size.
These reports can be generated after a Mailbox Content & Attachment gathering has been run.
Please see the following solution on how to setup the Content and Attachment gathering in Mesasgestats.
https://support.quest.com/kb/69474 - Video - How to create an Exchange Mailbox Content and Attachments gathering?
