Shared mailboxes in Exchange Online

Exchange Online

Applies to: Exchange Online

Topic Last Modified: 2017-10-09

A shared mailbox is a mailbox that multiple users can use to read and send email messages. Shared mailboxes can also be used to provide a common calendar, allowing multiple users to schedule and view vacation time or work shifts.

Shared mailboxes aren't supported on mobile devices.

Why set up a shared mailbox?

  • Provides a generic email address (for example, or, that customers can use to inquire about your company.

  • Allows departments that provide centralized services to employees (for example, help desk, human resources, or printing services), to respond to employee questions.

  • Allows multiple users to monitor and reply to email sent to an email address (for example, an address used specifically by the help desk).

Shared mailboxes make it easy for a specific group of people to monitor and send email from a common account, like public email addresses (for example, or When a person in the group replies to a message sent to the shared mailbox, the email appears to be from the shared mailbox, not from the individual user.

Shared mailboxes are a great way to handle customer email queries because several people in your organization can share the responsibility of monitoring the mailbox and responding to queries. Your customer queries get quicker answers and related emails are stored in one mailbox.

A shared mailbox doesn't have its own user name and password like a user mailbox does. You can't sign in to a shared mailbox directly using Outlook, Outlook Web App, Exchange ActiveSync, Exchange Web Services (EWS), or any other Exchange protocol. You must first be granted permissions to the shared mailbox, and then you access (open) it by using Outlook or Outlook Web App.

A user must have an Exchange Online license in order to access a shared mailbox. Shared mailboxes don’t require a separate license.

You can use the following permissions with a shared mailbox.

  • Full Access   The Full Access permission lets a user open the shared mailbox and act as the owner of that mailbox. After accessing the shared mailbox, a user can create calendar items; read, view, delete, and change email messages; create tasks and calendar contacts. However, a user with Full Access permission can’t send email from the shared mailbox unless they also have Send As or Send on Behalf permission.

  • Send As   The Send As permission lets a user impersonate the shared mailbox when sending mail. For example, if Kweku logs into the shared mailbox Marketing Department and sends an email, it will look like the Marketing Department sent the email.

  • Send on Behalf   The Send on Behalf permission lets a user send email on behalf of the shared mailbox. For example, if John logs into the shared mailbox Reception Building 32 and sends an email, it look like the mail was sent by “John on behalf of Reception Building 32”. You can’t use the EAC to grant Send on Behalf permissions, you must use Set-Mailbox cmdlet with the GrantSendonBehalf parameter.

Using a user account that has full access to a shared mailbox, in order to set up the Outlook profile of a shared mailbox is fully supported.

You can use the Exchange admin center (EAC) to create a shared mailbox in one step. Just navigate to Recipients > Shared mailboxes to view all the management tasks for shared mailboxes. For details, see Create a shared mailbox.

After you've created and assigned permissions to a shared mailbox, users can access the shared mailbox by using Outlook or Outlook Web App. For details, see:

In previous versions of Exchange Online, you could use a regular user mailbox as a delegated mailbox. If you have delegated mailboxes, you can use the Exchange Management Shell to convert those delegate mailboxes to shared mailboxes. For details, see Convert a Mailbox.


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