Go to System settings → Microsoft 365 integration settings

Enter the credentials provided by the administrator and click Generate Device Code.

You’ll get to see a message as shown: 

Sign in to the Microsoft account using the link and enter the device code to authenticate.

And here in this instance, click the Continue button.

Click the Test Connection button to test the connection..

And click Save to save the settings.

To create new hold with M365 integration, Go to Manage Holds → Create New Hold

Fill in the Hold Summary Step and click Save Continue  to create a hold.

Once you click Save Continue, you'll get to see the Legal staff step. 

Go back to the Hold summary step,  you’ll see the eDiscovery case name as shown;it has two parts: hold name and the hold number.

In the Hold notice step , you’ll  see the message  as shown:

Turn on the toggle Add Microsoft 365 Data Sources to add M365 data sources.

If the toggle is turned on, you’ll get to see the new tab Add Microsoft 365 Data Sources.

You can send  data sources to Microsoft by enabling the toggles Mailboxes,Onedrives and Teams.

Individual checkboxes for each person can also be utilized to choose individual datasources. 

Select all Data Sources button can be utilized to select all data sources at once.

In the Review and Send step, you’ll get to see the recipient's count message that includes eDiscovery Custodians count as well. 

Click Initiate Preservation in Microsoft 365 to migrate the custodian data sources to Microsoft.

Sample M365 page is as follows:

To see the assigned data sources for each user, select a user from the list and go to Locations tab.

Once the M365 preservation is initiated, you’ll get to see a new option click here to review the status of preservation.

On clicking the option, you'll see the preservation status as shown:

You can click the refresh icon to refresh the statuses.

Note: An error in the custodian records represents an error while synchronizing the custodian or data sources. You may click the re-sync icon to fix it.

And click Send to send the hold out, and put the custodians and data sources on hold in Purview.

You’ll get to see the hold created as shown:

For more details click on Recipients without responses.

To see the updated Custodian data sources in M365, click the Refresh button.

You can see the status is updated.

To release custodians, from the hold responses select the custodian  items to release and click Release custodian(s).

In the page that appears, add the custodian release date along with comments.

And click the Release custodian(s) button.  

You can turn off the optional toggles, depending upon what you want to send when releasing a custodian.

In the popup window, click the Yes, release custodian(s).

Under Add Microsoft 365 DataSources tab, you’ll get to see this information as shown:

You can see these changes on the Microsoft page as well.

Released custodians will show the status as Released and Hold status as False.

Go to System settings → Microsoft 365 integration settings

Click Reset settings to reset the old settings.

Click the Yes, reset my settings.