Microsoft Exchange: Powershell Script to add a SMTP Address to all users.

Recently during an Exchange to Office 365 Migration a bunch of the mailboxes were not part of the default SMTP address policy, and therefore didn’t get the “@domain.mail.onmicrosoft.com”

Instead of trying to update them all manually I just wrote a quick script to add the address with their default alias just so we could get them moved to Office 365

#################################################
#   Add new SMTP address to all mailboxes.      #
#   Created by - Cameron Joyce                  #
#   Last Modified - Jun 04 2017                 #
#################################################
# This script will add a new SMTP address for each mailbox on a specificed Exchange server.
# This script must be run from the Exchange Management Shell for Exchange 2010 - 2016

$mailboxes = Get-Mailbox -server servername

Foreach ($mailbox in $mailboxes){
    $name = $mailbox.alias
    Set-Mailbox "$name" -EmailAddresses @{add="$name@domain.com"}
}