Outlook 2010: Adding a rule for internal/external emails

After banging my head against my desk in frustration for months, I finally figured out a way to create a rule in Outlook that moves emails sent from an internal address. First I tried using the “specific words in the sender’s address” condition, using my company’s domain name as the word. This works for any specific external domains but it didn’t work for me in this case. My guess is that Exchange email addresses are represented differently behind the scenes, causing a bug in this filter.

The solution is to create a condition “with specific words in the message header”, and use this string: X-MS-Exchange-Organization-AuthAs: Internal

The result should look something like the following:


You could also use -AuthAs: Anonymous to catch external emails. I only tested this in my current setup, using Outlook/Exchange 2010. It probably won’t work if you don’t have Exchange as your email server.