What’s the Scenario?
Suppose an employee has resigned or quit the organization. Now, you are an administrator who has to convert that user’s mailbox into a shared mailbox to free up the mailbox license but, you also need the make the mailbox information available. How will you do this?
In order to do so, you need to convert a user’s mailbox into a shared mailbox and all the existing emails and calendars will be retained after this. Now, this shared mailbox can be accessed by multiple members, and later you can convert it back into a private user mailbox.
Recommendation: To know the shared mailbox & steps to create shared mailbox in Office 365.
So, if you already have removed the license then, add it back so that you can convert the user mailbox. Once the user mailbox gets converted, you can remove the license from it.
In order to remove the license, you have to delete so many large-sized emails along with attachments from the shared mailbox to minimize its size.
1: Sign in to your Office 365 admin account and navigate to Office 365 admin center.
2: In the admin center, click on Admin Centers >> Exchange.
3: Select Recipients and click on Mailboxes.
4: Highlight the User mailbox and click on Convert from Convert to Shared Mailbox
5: In case if the mailbox size is less than 50 GB then, you can delete the license from the user mailbox to eliminate the subscription charge.
But, do not delete the old user mailbox as the shared mailbox needs it as an anchor. A user cannot sign in with the old account
6: If you are a global admin then, you can use PowerShell to convert a user mailbox to a shared mailbox on-premises. For this, execute the following command:
set mailbox - type shared
If you have deleted the user account but, you need to convert the old mailbox to a shared mailbox then, follow the steps given below:
Step 1. Restore the User Account in Office 365
Restoring a user account within 30 days after deletion will restore the account along with entire data.
A user can sign in with the same account. But, make sure there are Office 365 licenses available that you can assign to account and you must have admin permissions to do so.
1: Go to the Office 365 admin center.
2: In the Admin center, click Users >> Deleted Users.
3: From Deleted Users list, select the one you want to restore and click Restore
4: After this, just follow the prompts to check the password
Step 2. Convert Restored User Mailbox to Shared Mailbox Office 365 – Steps
1: Go to the admin center and click on Admin centers >> Exchange.
2: Select Recipients and click on Shared.
3: Highlight the shared mailbox you want to convert and click on Convert from Convert to Regular Mailbox (user mailbox).
4: Navigate back to admin centers and select the user account that is associated with the old shared mailbox from Users. Next, assign a license to this account and reset its password.
The mailbox set up may take some time and then, a user can use the converted mailbox. After signing in, they can access the emails and calendars of the shared mailbox.