If you are planning to modify or change SMTP addresses in your Exchange 2010 environment there are a several things you will need to look out for. For purposes of this article we will focus on finding out which user mailboxes will not get updates from your Exchange 2010 “Email Address Policies”. This is determined by the “Automatically update email addresses based on e-mail address policy” option on the screenshot below. If there is a check a users mailbox will get the updated email address. If unchecked, no changes will be made to the mailbox.
To obtain a list of all mailboxes that will not get update when you change your “E-mail Address Policies” in Exchange you can run the command below. The command is in it’s basic format
Get-Mailbox -ResultSize Unlimited | Where {$_.EmailAddressPolicyEnabled -eq $False}
If you wanted to list all users whose mailboxes have the Automatically update email addresses based on e-mail address policy option turned on or checked just change the False to True
Get-Mailbox -ResultSize Unlimited | Where {$_.EmailAddressPolicyEnabled -eq $True}