One thing I still find with users is that they love to mistype URLs! One common mistake is to enter in the Outlook Web Access URL without specifying the https:// prefix, so here’s how we can have http:// automatically redirect to https:// for the OWA directory

Note: this is based on a Small Business Server 2008 install although can apply to any standard Exchange 2007 setup

Step 1) Open up the IIS Console and expand the appropriate Site containing the OWA folder. Select the OWA folder.
Step 2) Open up the Error Pages icon.

You should now see a list of the default error pages

Step 3) On the right side of the window under Actions click Add

Step 4) Create the following custom error page and click Ok

Status Code: 403.4
Select Respond with a 302 redirect
Enter the full HTTPS URL to your OWA location e.g. https://mail.mydomain.com/owa


Step 5) Test the redirect is now working from a client machine