Create an Organizational Unit (OU) in Active Directory.
- Move all users who need aliases into this OU.
- Example OU: OU=AuthN_Users,DC=domain,DC=com

Right-click the AddAlias.ps1 file and choose Edit (or open with Notepad/VS Code).
Update Line 1:
- Change the OU path to match your environment.
- # Replace this:
  $Users = Get-ADUser -Filter * -SearchBase "OU=TestUsers,DC=domain,DC=com"
- # With your OU path (Example):
  $Users = Get-ADUser -Filter * -SearchBase "OU=AuthN Users,DC=contoso,DC=com"
Update Line 4:
- Change the alias domain to match yours.
- # Replace this:
  "smtp:$($user.samaccountname)@new.domain.com"
- # With your alias domain (Example):
  "smtp:$($user.samaccountname)@authn.domain.com"
Save the file.

📝 Guide to create aliases for multiple users using Powershell