When your users want to open a document (PDF, MSG, etc…) from a document library and it keeps asking them to save instead of simply open them, you will have a lot of complaints to answer . . . but don’t quit your job yet, there is a solution.
Usually this happens due to security policies in the browsers and Sharepoint by default sets it’s browser file handling settings to Strict. If you search for a solution you will find hundreds of articles saying that all you have to do is to set this browser file handling configuration to Permissive and that will do the trick . . . well!!!
You will apply this setting and then test it, if it works GREAT! but if not . . . you will then search some more and find more dozens of articles that will guide you in development and IIS configuration. Well let me just say that I found a very usefull and more practical article from John Whites blog on this subject and it works like a charm 
The article is called Opening PDF Files in SharePoint 2010 and is shows how you can use Powershell to solve the problem.
Good work John!
Ricardo Magalhães
