im creating a credit card applicatoin that has to read increase Contacts Information (like telephone number, email, etc..) from Microsoft Exchange...

Does anyone know how do i connect with a MS Exchange DB ??

WebDAV is exactly what i personally use...

Here is a function i authored to gain access to our exchange server (be kind i authored it years back).. (:

 /// <summary>
    /// Returns XML string for a specific query
    /// </summary>
    /// <param name="Query"></param>
    /// <param name="Account"></param>
    /// <param name="Folder"></param>
    /// <returns></returns>
    private string ProcessRequest(string Query, string Account, string Folder) {

     System.Net.WebRequest req = WebRequest.Create("http://" + MailServer + "/exchange/" + Account + "/" + Folder);
      req.Headers.Add("Depth", "1");
      req.Headers.Add("Brief", "t");
      req.Credentials = ncCurrent;

      Byte[] bytes  = System.Text.Encoding.ASCII.GetBytes(Query);
      req.ContentType = "text/xml";
      req.ContentLength = bytes.Length;
      req.Method = "SEARCH";

      System.IO.Stream oStreamOut = req.GetRequestStream();
      oStreamOut.Write(bytes, 0, bytes.Length);

      WebResponse rsp = req.GetResponse();
      System.IO.Stream oStreamIn = rsp.GetResponseStream();
      System.IO.StreamReader oStreamRead = new System.IO.StreamReader(oStreamIn);
      return oStreamRead.ReadToEnd();

and here's the way i invoke it

  string xmldata = "<?xml version= \"1.0\"?>" +
    "<g:searchrequest xmlns:g=\"DAV:\">" +
      "<g:sql> Select \"DAV:href\" , \"urn:schemas:httpmail:subject\" " + 
      "FROM Scope('SHALLOW TRAVERSAL OF \"/exchange/" + Account + "/" + Folder + "\"') " +
      "</g:sql>" +

  XmlDocument d = new XmlDocument();
  d.LoadXml(ProcessRequest(xmldata, Account, Folder));

hopefully this points you within the right direction

You'll have to use Extended MAPI, it's not a typical SQL database.

If you work with Exchange 2007 you should use Exchange Web Services

You are able to:

Use ExtendedMAPI. Search for MAPI33 around the 'net. It's good examples of the items for you to do I believe.

Make use of the web services. Thats the most well-liked means by 2007

WebDAV also works, however i dont think it really works in 2007 whatsoever?

MAPI is the greatest way, but it is not formally supported insInternet (tho it really works), and it doesn't Whatsoever operate in 64bit mode. It's 32 bit only.