Shared mailboxes in Exchange Online
Applies to: Exchange Online
Topic Last Modified: 2015-04-27
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.
Why set up a shared mailbox?
Provides a generic email address (for example, email@example.com or firstname.lastname@example.org), 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, email@example.com or firstname.lastname@example.org). 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. You can't log into a shared mailbox directly using Outlook or Outlook Web App. You must first be granted permissions to the shared mailbox, and then you access it using Outlook or Outlook Web App. You don’t need to assign licenses to shared mailboxes, except when they are over their storage quota of 50 gigabytes (GB). If your shared mailbox goes over its quota of 50GB and you don’t assign it a license, after one month the shared mailbox will be locked. You can avoid having to assign the license by using archiving to avoid going over your quota.
You can use the Exchange admin center (EAC) to create a shared mailbox in one step. For details, see Create a shared mailbox. Just navigate to Recipients > Shared mailboxes to view all the management tasks for shared mailboxes.
You can use the following permissions with a shared mailbox.
Full Access The Full Access permission lets a user log into the shared mailbox and act as the owner of that mailbox. While logged in, the 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.