Another one of those things that you might use once in a blue moon. I had to retrieve a list of all smtp addresses from our Exchange 2007 environment for validation. We had multiple smtp addresses for each recipient so this could have been quite a daunting task but is actually straight forward. Here’s the powershell…

Get-Mailbox | select -expand EmailAddresses | %{$_.SmtpAddress} > emailaddresses.csv

Simple really!