Importing data into Office 365 from the Security & Compliance Center
When you have all of your mailboxes migrated to Exchange Online, it is possible—and highly likely—that some users in your organization will have one or more .pst files stored on their local computers. This is due to the fact that archiving older mailbox content from Exchange on-premises mailboxes used to be a standard operating procedure for most organizations due to the limited storage capacity of Exchange Mailbox databases.
This creates an issue in that although your users' main mailbox has been migrated and now resides in Exchange Online, there could also be a significant amount of mailbox data scattered across various devices within your environment and, as such, this data is not protected by the compliance features available within Office 365.
In order to help IT administrators solve this problem, Microsoft has provided the Import feature, which can be found in the Information governance...
