There’s two ways to disable Missed Call Notifications:
- At the UM Mailbox Policy
- On a UMMailbox
When viewing an existing UM Mailbox Policy, you will see the “Allow Missed Call Notifications” option which is enabled by default.
Disabling this option in Exchange 2007 does nothing as there is currently a bug in Exchange 2007 that prevents this from working. According to a Microsoft employee I talked with, this bug is postponed and is fixed in Exchange 2010 and does not believe this will be fixed in Exchange 2007. You never know though. It may end up being fixed.
The alternative is to excplicitly disable this for UM enabled users.
If you run the following command, you can disable the option for a specific user:
Set-UMMailbox User -AllowMissedCallNotificationEnabled $false
Of course you can also use piping so you can get all UM Mailbox Users and disable it in bulk. For example:
Get-UMMailbox | Set-UMMailbox -AllowMissedCallNotificationEnabled $false