To solve this you normaly do the following:
- Create SMTP connector your users will use for sending mails
- This connector must require user authentication
But unfortunally Exchange does still return a error message like:
"550 5.7.1 Client does not have permission to send as this sender"
To solve this, you have to allow all authenticated users to send mails via this connector.
This can be done via the Exchange shell with this command:
Add-AdPermission -Identity "MySMTPConnector" -User "NT AUTHORITY\Authenticated Users" -ExtendedRights ms-Exch-SMTP-Accept-Any-Sender
Unfortunally non-english servers just won't find the corresponding group, since it is named differently (Read localized)
To find out the correct group name you can use this command:
Get-Adpermission -Identity "MySMTPConnector" | format-table -view identity
For a german installation the corresponding group is "NT-AUTORITÄT\Authentifizierte Benutzer"
So the final command for the german exchange server is:
Add-AdPermission -Identity "MySMTPConnector" -User "NT-AUTORITÄT\Authentifizierte Benutzer" -ExtendedRights ms-Exch-SMTP-Accept-Any-Sender