The process of configuring SMTP journaling uses both the Commvault software and Office 365 with Exchange.
Before You Begin
You must have a thorough understanding of journaling and of defining journal rules for Office 365 with Exchange. Consult the Microsoft documentation before you install and configure the ContentStore Mailbox. For example, see these articles on the Microsoft TechNet:
"Configure Journaling in Exchange Online", https://technet.microsoft.com/en-us/library/dn781273(v=exchg.150).aspx
"Manage journaling", https://technet.microsoft.com/en-us/library/jj651670(v=exchg.150).aspx