Connecting to a Shared Mailbox

What is a Shared Mailbox?

A Shared Mailbox is a mailbox that allows multiple users to read and send messages. Shared Mailboxes are typically email addresses that are used as a centralized point of contact (for example: a Human Resources department may create a shared mailbox for employees to write to, and then have Human Resources team members monitor and reply to emails sent to the mailbox).

Mailbox Permission Levels

There are three levels of permission that can be designated to users of 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 John Doe logs into the Human Resources shared mailbox and sends an email, it will look like Human Resources 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 Doe logs into the Facilities shared mailbox and sends an email, it will look like the mail was sent by "John on behalf of Facilities"

Accessing Shared Mailboxes

Shared Mailboxes do not have their own usernames or passwords, therefore, you do not log into them directly. In order to access a shared mailbox, users must first be granted permissions to the mailbox. If you would like to request permissions to a shared mailbox, please reach out to the ITG Help Desk.

Once you have been granted access, follow the instructions below to open the shared mailbox in Outlook:

  1. On the top menu bar, navigate to Zimbra Open Other User's mailbox.
  2. In the Select Mailbox search field, type in the name of the user that shared a portion of their IAS mailbox with you. Select the entry that appears with in the E-mail Address column.
    • For example, if user jdoe shared a portion of their IAS mailbox with you, you would search for and select the entry that appears as
      Screenshot of Select Mailbox dialog box in Microsoft Outlook 2019
  3. Click OK.
  4. Go to the appropriate section in your IAS mailbox that the user shared with you (e.g. Calendar, Contacts, etc.). You should see a listing for the user that shared that portion of their IAS mailbox with you.
    • For example, if user jdoe shared their calendar with you, when you display your calendar you will see an entry for jdoe - Calendar.