Script to Compare List of Email Addresses in Exchange

I was provided a list of email addresses of employees in a system that doesn’t interface with AD/Exchange and asked to validate those email addresses exist within our Exchange server. I figured the easiest way was to just script it (the list was close to 1000 people).  Total run time to compare the list was just a few seconds.

Here’s the (quite simplistic) script to accomplish the task.

$logFile = 'c:\scripts\IsAccountValid.log'

# Uncomment the entry below if not running from the EMS
# Add-PSSnapin Microsoft.Exchange.Management.PowerShell.Admin

# Import the email addresses from text file
$Import=Get-Content "c:\Scripts\emailaddresses.txt"

ForEach ($address in $import) {
     $valid = get-mailbox -an $address
          If ($valid) {
          "$address is Valid" >> $logFile
          } else {
          "$address is Not Valid" >> $logFile
          }
}