As well as having to Skype enable all users recently (see previous post) I also had to mailbox enable the users. With Exchange 2010 you can’t just import the powershell module. Using this article as a base I came up with this; $Session = New-Pssession -COnfigurationName Microsoft.Exchange -ConnectionUri http://exchangeservername/powershell Import-Pssession $Session Get-User -OrganizationalUnit “OU=ExampleOU,DC=Example,DC=Com” | Enable-Mailbox -database “your mailbox database”