Applies to All Versions
When you create any distribution list in Exchange Management Console (EMC) by default sender authentication is enabled in order to prevent any unwanted messages or spam from outside domains.
In order to send e-mails via a distribution list, you will have to disable the sender authentication. You can do this in the following area of your EMC:
Recipient Configuration -> Distribution Groups -> Select a group -> Properties -> Mail Flow Settings -> Message Delivery Restrictions -> Properties -> Untick “Require that all senders are authenticated”
This will allow a distribution list to receive e-mail from your intranet software.