Remove Auto-mapped Mailboxes from Outlook

You can remove auto-mapped mailboxes from Outlook by using the following steps:

Troubleshooting Steps:

Open an elevated Windows PowerShell and then enter the following commands:

1. Set-ExecutionPolicy RemoteSigned
2. Install-Module -Name ExchangeOnlineManagement
3. Import-Module ExchangeOnlineManagement
4. Connect-ExchangeOnline (It will ask for your credentials please enter the credentials for your Global Admin account)
5. Add-MailboxPermission -Identity <shared mailbox alias> -User <your mailbox alias> -AccessRights FullAccess -InheritanceType All -Automapping $false