Custom C# application and Exchange Server 2003 integration over WebDAV was one of the tasks I lately worked on. I made posting about how to log on to Outlook Web Access when FBA is used but I didn’t mentioned that I had to read data from Exchange public folders. There are some stuff that may drive you nuts but there are also some tricks to use to get everything work as expected.
- Use Fiddler2 to monitor IE <=> OWA and your application <=> OWA traffic. Don’t use Fiddler 1.x if OWA is accessed over HTTPS. I wasn’t able to see any HTTPS responses with Fiddler 1.x although I used special extension they recommend.
- Compare requests made by IE to ones made by your application. Pay attention also to character encodings. If you have multi-byte characters in URLs then make sure your application creates same URLs as IE does.
- You have to modify default settings of HttpWebRequest object because some default values it uses are not same as IE defaults. Just check out HTTP header sent by IE and exceptions thrown by HttpWebRequest.
- Make sure that your application runs under credentials that have permissions to make outbound connections.
I hope it helps somebody. :)