How to Add Shared Mailbox in New Outlook

To add a shared mailbox in Microsoft 365, you can use the Outlook Web App or the admin center. You'll need admin permissions to create a shared mailbox.

• Using the Outlook Web App
• Sign in to the Outlook Web App
• Select Folders from the navigation panel
• Select More
• Right-click your name
• Select Add shared folder
• Enter the name or email address of the shared mailbox
• Select Add

Using the admin center to Add Shared Mailbox

• Go to the admin center
• Go to the Teams & Groups page
• Select Shared mailboxes
• Select + Add a shared mailbox
• Enter a name for the shared mailbox
• Select Save changes
• Select Add members to this mailbox
• Select the people you want to add to the shared mailbox
• Select Add

Shared mailboxes can be used for a shared calendar, sending and receiving emails, or using a shared email address.

More months have passed and this is still broken.

It seems Microsoft cannot even support their own stuff properly.

Too bad, i was looking forward to this

I have finally been given a solution to this issue, after many, many back-and-forths with Microsoft. Not sure why they wouldn't release this information to admins when they started pushing New Outlook, but I'm at least glad to have finally found a working answer.

Essentially, you need to follow the steps in this article.

Troubleshoot shared mailboxes in new Outlook - Deploy Office | Microsoft Learn

You will be setting the mailbox policy to true with the following attribute:

-OneWinNativeOutlookEnabled $true

I opted to use the second option, 'Custom OWA Mailbox policy' so I could test before pushing this policy to all mailboxes in our organization.

I did eventually set the Default as well, and have not noticed any unexpected changes to the applied mailboxes.

Hopefully others following along can apply this and finally have this issue behind them!

I don't think it counts as a game changer as the function works perfectly in old outlook and new outlook broke something that was completely functioning.

The issue is not with the Calendar, it is with accessing the Shared Mailbox for the account. While I can add the calendar without any errors, this does not make the mailbox work.

I am the administrator and I have given myself full read and manage permissions to the Shared Mailbox. Permissions is not the cause of this issue, rather a broken feature in the app.

Hello All,

Make sure your administrators have given you read and manage permissions for that specific Shared Mailbox
Now, if a new calendar has been created by Shared mailbox you should be able to add calendar manually.
Make sure the calendar you are trying to access has been shared with you.

First click Add Calendar, then select Edit my calendar OR use Add from Directory.
Type the name of external or shared mailbox email address and it should let you select it and add to list.