sbs 2008 cannot send to distribution group emails from outside exchange

Just in case you are looking for the answer to this problem as well......  took me 15 mins to find what should be a super easy question.

https://social.technet.microsoft.com/Forums/exchange/en-US/56e342e4-1aed-4164-a7b9-0e5fabf102f0/cannot-send-to-distribution-group-emails-from-outside-exchange?forum=exchangesvrgenerallegacy




Question:I have created several emails linked to distribution groups in Exchange 2007.  When i email to these groups from an email hosted on the server the email goes through just fine.  When I try to send to these emails from an external email address (one from  hotmail or  yahoo) the email is never received and I never get a message back saying anything went wrong. I am able to receive email to all normal user accounts.  I know it was possible in Exchange 2003 to have group emails receive email from outside sources, as I used several group emails as logins at various forums, and received updates from them. 

 

Am I missing some point of the setup?  I have all domains open to be received from, hence why I can receive to my normal user email address.  Any help would be appreciated.

 

Thanks



Answer:   

When you create any distribution list with Exchange Management Console - EMC or Exchange management Shell - EMS in 2007 by default Sender Authentication is Enabled to prevent unwanted messages from spam and from outside domain, this is by default in design...

 

You need to disable it to get email from outside.

 

From EMC: Recipient Configuration -> Distribution Groups -> Select a group -> Properties -> Mail Flow Settings -> Message Delivery Restrictions -> Properties -> Untick “Require that all senders are authenticated”