Why You Need to Add a Shared Mailbox as an Additional Mailbox in Outlook

Shared mailboxes are an essential tool for team collaboration, allowing multiple users to access and manage emails, calendar events, and other data collectively. While automapping automatically links shared mailboxes to your Outlook profile, adding a shared mailbox as an additional account manually offers several advantages. Here’s why this approach is beneficial and how you can set it up.

Event Reminders

Outlook doesn't show event reminders for a mailbox that is automapped or added as an additional mailbox. To get reminders for a shared mailbox, you need to add it as an additional account in your Outlook profile. This way, you won't miss important events.

Improved Functionality

Adding the shared mailbox as an additional account can improve how it works. You can see event reminders and manage sent items better. This makes your email and calendar more organized.

Avoiding Confusion

When a shared mailbox is added automatically with your primary mailbox, Outlook might get confused about who "you" are. This can lead to all email addresses being included in a "Reply to All." Adding the shared mailbox as an additional account helps avoid this confusion.

Better Performance

Adding a shared mailbox as an additional mailbox can make Outlook run better, especially if you have multiple shared mailboxes. Automapping can slow down Outlook, but manually adding shared mailboxes can keep it running smoothly.

Client-Side Rule

If you want to create a rule to play a sound when you receive an email for a shared mailbox, it won't work with server-side rules. Server-side rules can't access the local resources needed to play the sound. By adding the shared mailbox as an additional account, you can create client-side rules that perform actions like playing a sound when an email is received.

How to Add a Shared Mailbox as an Additional Mailbox

Step 1: Re-add Permission to the Shared Mailbox Without Automapping

In Microsoft Outlook, Autodiscover automatically maps to any mailbox for which a user has full access permissions. This can cause performance issues if the user has full access to many mailboxes. To disable automapping on a mailbox, use Exchange Online PowerShell to remove the user's full access permissions from the mailbox, and then add the permissions back with automapping disabled.

• Connect to Exchange Online:

Connect-ExchangeOnline        

• Remove the user's full access permission from the mailbox:

Remove-MailboxPermission -Identity <MailboxIdentity> -User <UserIdentity> -AccessRights FullAccess        

• Grant full access permissions back to the user with automapping disabled:

Add-MailboxPermission -Identity <MailboxIdentity> -User <UserIdentity> -AccessRights FullAccess -AutoMapping $false        

Step 2: Add the Shared Mailbox as an Additional Account in Outlook

1. Open Outlook and select File > Add Account.
2. Enter the email address of the shared mailbox and select Connect.
3. When prompted to sign in, enter your email address instead of the shared mailbox's email address and select Next.
4. If the sign-in prompt doesn't let you change the email address, select Sign in with another account to open a new sign-in prompt, and then enter your email address and password.
5. After successfully authenticating, restart Outlook.

Important Note: The Full Access permission allows a user to open the mailbox as well as create and modify items in it. The Send As permission allows anyone other than the mailbox owner to send email from this shared mailbox. Both permissions are required for successful shared mailbox operation.

By following these steps, you can ensure that your shared mailbox is added as an additional account, providing you with better functionality, performance, and overall email management experience.