Goal:
Use a powershell script that will take every user in the Active Directory and change their email address to [alias]@domain.com.
Background:
I was recently working on a migration for a company to move them from in house Exchange to Office 365 Exchange. I used some powershell scripts to perform a few of the functions to change mailbox users to email enabled users. In the process afterwards I somehow accidentally set all the email addresses to firstname.lastname@domain.com The problem is that this isn't truly their email address. There isn't a common pattern for all of the users, but luckily the alias didn't change. So I'm hoping to pull that value to use in making things right.
It is Exchange 2010 if that makes a difference. We have 2008 servers (and possible a 2008 r2 in the