Block MS Exchange Server OWA access from Internet

For restrict Outlook Web Access (OWA) from the internet follow below simple steps.

• Install “IP and Domain Restrictions” server sub role in Web Server > Security.

• Open IIS Manager and Go to Default Web Site > owa > IP Address and Domain Restrictions.

• Add Allow Entry/entries from Actions view. Add your local network sub nets in here.

Add Deny Entry for unspecified clients.

That’s it.