How to Retain Emails of departing Employees without using Exchange Online License ?
In a scenario where the requirements of compliance are increasing, the Organizations are expected to retain the Emails of departing users for a certain period of time. Now if Companies are forced to do it by retaining the User license, then the cost of licensing in Office 365 would increase.
Fortunately, Office 365 gives us a way to do so without blocking the license for departing user. The feature is called “Inactive Mailbox ”. And it is available in Exchange Plan P2 . So this will work with Exchange P2 or Office 365 E3 Plan. See Office 365 Plan Comparison
The complete process involves using a combination of In Place Hold, Litigation Hold + Inactive Mailbox + E Discovery.
If your organization needs to archive mailbox content for departed employees, you can turn the mailbox into an inactive mailbox by placing it on In-Place Hold or Litigation Hold , Next you remove the corresponding Office 365 account. Another way would be for the account to remain without the Office 365 license. The contents of an inactive mailbox are preserved for the duration of the hold that was placed on the mailbox before it was made inactive.
Please check the screen shot below. It shows that a user mailbox has been put under in-place hold:
In the screen shot below, you can see that there is no license assigned to the same user:
Access Inactive Mailbox Contents
Once the mailbox is in the Inactive state, it is possible to search for email content via eDiscovery mechanisms in Exchange Online, as well as recover, restore or delete the data as required.
Note that Inactive Mailboxes do NOT require a license.
You can get more details of this superb compliance feature at the link here