Microsoft 365 Shared Mailbox is a really cool feature for an Organization when it requires multiple people to need access to the same mailbox, such as company information or support email address, reception desk, marketing details, or other function that might be shared by multiple people in a team.
As an Office 365 administrator, one can create a shared mailbox, assign permission to the group of users that allows users to send and receive emails through the shared mailbox which has its own unique email address. This is particularly useful for help and support mailboxes because users can send emails from “Company Support” or “From the Reception Desk.” tag to the receivers.
In this blog, we are detailing some of the important features of a shared mailbox, creating a shared mailbox in Office 365 environment, converting a user mailbox to a shared mailbox, etc.
Considerations before creating a shared mailbox
As an Exchange administrator below is the few things listed should know before creating a shared mailbox.
Membership permissions – Before creating a shared mailbox, you should know the members who can access the shared mailbox. After providing the access permissions, members can access the shared mailbox in his mailbox directly.
License considerations – Generally a shared mailbox does not require a license, however, if the shared mailbox data exceeds 50 Gb, you need to assign a license to the shared mailbox to store more data
No Email encryption – A shared mailbox is not an encrypted mailbox against user mailboxes. Because a shared mailbox does not have its own security context ( username & password ) to have its own security key. If more than one person is a member, and they send/receive emails they encrypted with their own keys, other members might be able to read the email, and others might not, depending on which public key the email was encrypted with.
Subscription requirements – To create a shared mailbox, you need to subscribe to Microsoft 365 for a business plan that includes email (the Exchange Online service). Check your subscription before creating a shared mailbox.
Creating a shared mailbox in Microsoft 365 Exchange Admin Center
Users with global admin or Exchange admin roles can create shared mailboxes. So login to Microsoft 365 Admin Center using a Global admin account or an exchange admin account.
On the left side, expand Groups and choose Shared mailboxes. Choose the “ Add a shared mailbox” button to create a new shared mailbox as shown below in a red box.
On clicking the “Add a shared mailbox” button you will be asked to enter a Name and email id associated with the new shared mailbox you will be creating. Click Save changes.
You will get a shared mailbox created notification after a few minutes as shown below, and can follow the next step instructions further.
Adding members to the shared mailbox
On clicking the newly created shared mailbox, you will find the various exchange properties associated with the shared mailbox as shown below screenshot. Our next step is adding members to the shared mailbox. Click edit on the member’s property to add new members to use the shared mailbox in their mailboxes.
On clicking Add members, all created users in the Exchange admin center will be listed, and you can choose the users to be members of the shared mailbox. After adding the members the wizard will notify you to change effect in 60 minutes and can be accessed in Outlook and OWA
Other useful configuration settings for a shared mailbox
There are other email settings also available for the configuration of shared mailboxes. Users can edit each email setting at any time.
Email addresses – You could set a primary email address for the shared mailbox and can add aliases for the email address. The shared mailbox receives all emails sent to the primary email address. Creating aliases to give the shared mailbox alternate email addresses. Any email sent to an alias will be forwarded to the primary email address.
Email forwarding – You can designate an email address to forward all emails coming to the shared mailbox. The mailbox owner will be able to view and change these forwarding settings.
Automatic replies – Use these settings to create automatic reply (Out of Office) messages. When enabled, you can draft a customized reply to the sender. You could also restrict it to send only domain users or all external senders.
Manage sent items – Copy items sent as this mailbox, or on behalf of this mailbox, to the mailbox’s Sent Items folder. This lets shared mailbox members see the email other members have sent. If you don’t copy sent items to the mailbox, they will only be saved to the sender’s Sent Items folder.
Email apps – you could also enable/disable the exchange email apps for this shared mailbox. Available apps are Outlook on the web, Outlook desktop (MAPI), Exchange web services, Mobile (Exchange ActiveSync), IMAP, and POP services. By default, all services are enabled.
Litigation hold – When a shared mailbox is put on litigation hold, members can purge items from the mailbox, but those items will still be retained by Microsoft 365.
Manage mailbox permissions – In this mailbox permissions, you can set individual permissions for the members such as to “Read and manage “ “Send as” and “Send on behalf”
Show in global address list – Choose whether to show this mailbox in your organization’s global address list. If you don’t show it, new shared mailbox members won’t be able to add it to their Outlook profile until the shared mailbox is again shown in the address list. By default, it is enabled.
Converting a user mailbox into a shared mailbox
In most cases, a relieving employee’s mailbox in an Organization requires access by some of his team members. In this case, the Exchange administrator can convert an employee’s mailbox into a shared mailbox and give permission to his team members to access his received emails. When you convert a user’s mailbox to a shared mailbox, all of the existing email and calendar are retained.
Some important considerations before converting a user mailbox into a shared mailbox
- The user mailbox you’re converting needs a license assigned to it before you convert it to a shared mailbox.
- Shared mailboxes can have up to 50 GB of data without a license assigned to them. To hold more data than that, you need a license assigned to it.
- Don’t delete the old user’s account. That’s required to anchor the shared mailbox.
- The rules are intact after the mailbox is converted to a shared mailbox.
Login to Microsoft 365 admin center as a global admin or Exchange admin. Users choose Active Users. This will list down all active users. Choose the user whose mailbox is converted to a shared mailbox. It will show all the properties of that particular user mailbox.
Choose the “Mail” tab, Under “More actions” you can see the “Convert to shared mailbox” option. The below picture shows this option in the red color box mark.
On clicking the “Convert to shared mailbox” action, an information page says the below messages
Shared mailboxes let a group of people monitor and send mail from a common email address, like email@example.com. When you convert a user’s mailbox to a shared mailbox, all of the existing email and calendar items will be available to members of that mailbox.
Users won’t sign into a shared mailbox with a username and password, but people who are members of the mailbox can access it with Outlook.
Click Convert at the bottom of the page to proceed further. You will get a confirmation message as below. Click done to finish the conversion action.
After verifying the shared mailbox in the page Groups → Shared mailboxes, you can assign members to the newly created shared mailbox, and can access emails from their Outlook or OWA. For more information on accessing shared mailboxes in Outlook visit the following URL
Removing license from the shared mailbox
Usually, a shared mailbox does not require a license. So you can remove the license from the shared mailbox, once it is converted successfully. So that you can assign the removed license to some other newly created user. Follow the below steps to remove a license from the shared mailbox.
- Login to Microsoft 365 Admin Center as a Global Administrator or Exchange Administrator
- Choose Users → Active users → Select that particular user that was converted to a Shared mailbox.
- Choose Licenses and apps tab
- Untick Office 365 subscription under Licenses section
- Click Save changes.
The below picture shows this action, after unselecting the license Microsoft 365 E3 Subscription shown in the red box.
Deleting a shared mailbox
You can delete a shared mailbox anytime, as when not required. Follow the below steps to delete a shared mailbox. Before deleting a mailbox, you can remove the access permissions given to the users for that mailbox.
- Login to Microsoft 365 admin center as Global administrator or Exchange administrator
- Choose Groups → Shared mailboxes – Choose the shared mailbox to delete.
- Click on more actions ( three dots ), and choose the “Delete shared mailbox” button
The below picture shows this action and deletes the shared mailbox in the red box.
Shared mailboxes have several advantages over using individual mailboxes in many use cases.
The biggest benefit is that multiple team members can monitor and send emails from one account. Using a shared mailbox, allows teams to respond to customer inquiries faster if they configured a shared mailbox for support emails. Also, an Office 365 shared mailbox allows small businesses to keep all customer appointments in a single calendar. With this ability, everyone can easily see where team members are scheduled to be located any given day and which customers are being serviced. Also using the Office 365 admin center console, it is very easy to create a shared mailbox and give permissions to access the created mailbox in a few steps easily.