Setting up a Microsoft 365 shared mailbox for Zoom Contact Center email

Zoom Contact Center (ZCC) email supports Microsoft 365 shared mailboxes, so your team can receive and reply to customer emails from a shared address (for example, support@company.com) without requiring a dedicated Microsoft 365 license for the shared mailbox. This article covers how to create or identify a shared mailbox, grant the required permissions, connect the mailbox to ZCC, and verify the setup.

If you experience issues with your shared mailbox connection, visit Troubleshooting Microsoft 365 shared mailbox issues in Zoom Contact Center.

Requirements for setting up a Microsoft 365 shared mailbox

Account owner or admin privileges; or role with permission to manage connected email accounts
A Microsoft 365 shared mailbox (Exchange Online)
A licensed Microsoft 365 delegate user (with an Exchange Online license) who will authorize the connection. Shared mailboxes have sign-in blocked by default and cannot authorize the connection themselves.
- The delegate user must have Full Access and Send As (or Send on Behalf) permissions on the shared mailbox in Exchange Online. Zoom recommends Send As so replies present a single, consistent identity to your customers.
Exchange administrator or Global administrator role in Microsoft 365 to create the mailbox and assign delegation.
Your Microsoft 365 tenant must permit the Zoom Contact Center app to be consented. If your tenant requires admin consent, a Microsoft 365 admin must approve it once.

During the OAuth sign-in flow, ZCC requests the following delegated Microsoft Graph scopes:

Graph scope	Purpose
Mail.ReadWrite.Shared	Read, update, and manage messages in the shared mailbox on behalf of the signed-in delegate user.
Mail.Send.Shared	Send messages from the shared mailbox address so agent replies appear to come from the shared inbox.
Mail.ReadWrite	Read, update, and manage mail in the signed-in user’s own mailbox.
Mail.Send	Send mail as the signed-in user.
User.Read	Sign in and read the signed-in user’s profile, used to identify the delegate completing the authorization.
User.ReadBasic.All	Retrieve the shared mailbox’s profile. This permission is required to connect a shared mailbox; the request fails without it.
openid	Standard Microsoft sign-in permission.
profile	View the signed-in user’s basic profile.
offline_access	Maintain the connection without requiring the delegate to re-authenticate for every sync.

Important: Microsoft Graph scopes and Exchange mailbox permissions are two separate systems. Granting Graph scopes during sign-in does not grant permission to the shared mailbox itself. It must be configured separately in Exchange.

Limitations for setting up a Microsoft 365 shared mailbox

Gmail and Google Workspace shared inboxes (delegated mailboxes and collaborative inboxes) are not supported at this time.
Only delegated access is supported. Application-only (client credentials) access to shared mailboxes is not available for this integration.
S/MIME-encrypted email is not supported.
The connection depends on the delegate user’s account. If that account is disabled, unlicensed, or loses mailbox delegation, the connection stops working. Zoom recommends using a stable, IT-managed delegate account rather than an individual employee’s account.
Microsoft does not provide an API for querying which mailboxes a signed-in user has permissions for, so ZCC cannot validate Exchange mailbox permissions during setup.

How to set up a Microsoft 365 shared mailbox for ZCC email

How to set up a Microsoft 365 shared mailbox for ZCC email

Create or identify the Shared Mailbox in Microsoft 365

Sign in to the Microsoft 365 admin center as an Exchange administrator or Global administrator.
In the left navigation, click Teams & groups then Shared mailboxes, or click Show all if you don't see it.
Click +Add a shared mailbox.
Enter a display name and the email address customers will write to (for example, support@company.com).
Click Save changes.
Wait a few minutes for the mailbox to finish provisioning before assigning permissions.

Note: Shared mailboxes do not require a license under 50 GB. An Exchange Online Plan 2 license is required if the mailbox exceeds 50 GB, uses in-place archiving, or is placed on litigation hold.

Grant the delegate user Full Access and Send As

Without Send As (or Send on Behalf), ZCC will connect and receive mail successfully, but every outbound reply will fail.

Using the Exchange admin center

Sign in to the Exchange admin center.
Click Recipients then Mailboxes.
Select your shared mailbox.
Click the Delegation tab or select Manage mailbox delegation under Mailbox permissions.
Next to Read and manage (Full Access), click Edit and add the licensed delegate user, and save.
Next to Send as, click Edit, add the same delegate user, and save.
Wait up to 60 minutes for the permission change to replicate across Exchange Online before connecting the mailbox in ZCC.

(Optional) Using PowerShell

Admins who prefer PowerShell can run the following commands with Exchange Online PowerShell connected:

Add-MailboxPermission -Identity "support@company.com" -User "delegate@company.com" -AccessRights FullAccess -InheritanceType All

Add-RecipientPermission -Identity "support@company.com" -Trustee "delegate@company.com" -AccessRights SendAs -Confirm:$false

For a walkthrough of granting Send As, see Microsoft's documentation: Create a shared mailbox.

How to connect the shared mailbox in Zoom Contact Center

Sign in to the Zoom web portal as an admin with the privilege to edit account settings.
In the top-right corner, click your profile picture or initials, then click Admin Center.
In the side menu, click CX management .
Click Contact Center.
Click Preferences then Email Management.
Click Add Email Account and select Microsoft 365 / Outlook as the provider.
Select the Shared mailbox account type, then enter the shared mailbox address (for example, support@company.com).
Click Authorize.
You will be redirected to Microsoft to sign in.
Sign in as the licensed delegate user, not as the shared mailbox.
Review the requested permissions and click Accept. If your tenant requires admin consent, a Microsoft 365 admin must approve the request before setup can continue.
Back in ZCC, assign the connected account to the queue or flow that should handle its email engagements, then save.

Note: ZCC verifies the Microsoft Graph permissions at this point, but Microsoft does not expose an API that lets ZCC confirm Exchange mailbox permissions. A mailbox can therefore connect successfully and still fail on the first outbound reply if Send As was never granted.

How to verify the connection

Sign in to the Zoom web portal as an admin with the privilege to edit account settings.
In the top-right corner, click your profile picture or initials, then click Admin Center.
In the side menu, click CX management .
Click Contact Center.
Click Preferences then Email Management.
Confirm the Microsoft 365 account shows a status of Connected.
From an external email address, send a test message to the shared mailbox and confirm that an email engagement is created and routed to the expected queue.
Accept the engagement as an agent and send a reply. This step validates that Send As is working.
Confirm the reply arrives at the external address and that the From address shows the shared mailbox (for example, support@company.com) with no on behalf of prefix.

This integration uses delegated access. You connect the shared mailbox by signing in as a licensed Microsoft 365 user who has been granted permission to the shared mailbox. That user's delegated permissions, not the shared mailbox itself, authorize ZCC to read and send mail.