Outlook Anywhere offers the following benefits to clients that use Outlook 2013, Outlook 2010, or Outlook 2007 to access your Exchange messaging infrastructure:
Users have remote access to Exchange servers from the Internet.
You can use the same URL and namespace that you use for Outlook Web App and Microsoft Exchange ActiveSync.
You can use the same Secure Sockets Layer (SSL) server certificate that you use for both Outlook Web App and Exchange ActiveSync.
Unauthenticated requests from Outlook can’t access Exchange servers.
You don’t have to use a virtual private network (VPN) to access Exchange servers across the Internet.
If you already use Outlook Web App with SSL or Exchange ActiveSync with SSL, you don’t have to open any additional ports from the Internet.
You can test end-to-end client connectivity for Outlook Anywhere and TCP-based connections by using the Test-OutlookConnectivity cmdlet.