Hi Rahim,
Currently, it is not feasible that we send emails from the DG address in From in Outlook for Mac. It is a known issue. Thanks for your understanding.
You can submit feedback via the following link to let our engineering team hear your voice directly. If the service is requested frequently, it might be included in the future release.
http://support2.microsoft.com/common/survey.aspx?scid=sw;en-us;2222&altStyle=MFE&renderOption=OverrideDefault&showpage=1&fr=1&nofrbrand=1
Best regards,
Ran