Exchange WebDAV

[arjen1984]

I am now working on C# with WebDAV on Exchange now to get appointments. When I work local on the domain where the server is, i can get the appointments no problem. When I work outside of it, i get an SecurityExcepti on. This is my code to get the appointments:
protected void getAfspraken()
{
NetworkCredenti al credential = new NetworkCredenti al("bhees","123 4567", "oaicttest" );
WebdavSession session = new WebdavSession(c redential);
session.UserMai lbox = "http://192.168.0.56/exchange/bhees/";

Resource resource = new Resource(sessio n);

//retreive single appointment
//Appointment appointment1 = resource.GetApp ointment("http://myserver/exchange/Administrator/Calendar/appointment1.em l");

//retrieve all appointments from Calendar folder
Appointment[] allAppointments = resource.GetApp ointments();

//retrieve all appointments from specified folder
//Appointment[] testAppointment s = resource.GetApp ointments("http ://myserver/exchange/bhees/Calendar/Test");

//retrieve all appointments from specified public folder
//Appointment[] publicAppointme nts = resource.GetApp ointments("http ://myserver/public/Calendar");

Response.Write( allAppointments .ToString());
}

I get following errors:

Regel 98:
Regel 99: //retrieve all appointments from Calendar folder
Regel 100: Appointment[] allAppointments = resource.GetApp ointments();
Regel 101:
Regel 102: //retrieve all appointments from specified folder


Bronbestand: \\fs11\ao-ict\UserData\ah oeve\Mijn documenten\Visu al Studio 2005\WebSites\W ebSite2\Default .aspx.cs Regel: 100

Stacktracering:

[SecurityExcepti on: De aanvraag voor machtiging van type System.Net.WebP ermission, System, Version=2.0.0.0 , Culture=neutral , PublicKeyToken= b77a5c561934e08 9 is mislukt.]
System.Security .CodeAccessSecu rityEngine.Chec k(Object demand, StackCrawlMark& stackMark, Boolean isPermSet) +0
System.Security .CodeAccessPerm ission.Demand() +59
System.Net.Http WebRequest..cto r(Uri uri, ServicePoint servicePoint) +166
System.Net.Http RequestCreator. Create(Uri Uri) +26
System.Net.WebR equest.Create(U ri requestUri, Boolean useUriBase) +373
System.Net.WebR equest.Create(S tring requestUriStrin g) +81
Independentsoft .Webdav.Exchang e.Resource.r(St ring A_0) +786
Independentsoft .Webdav.Exchang e.Resource.c(St ring A_0, String A_1) +60
Independentsoft .Webdav.Exchang e.Resource.a(St ring A_0, PropertyName[] A_1) +1593
Independentsoft .Webdav.Exchang e.Resource.GetP roperties(Strin g address, PropertyName[] propertyName) +34
Independentsoft .Webdav.Exchang e.Resource.d(St ring A_0) +992
Independentsoft .Webdav.Exchang e.Resource.GetM ailbox(String userMailboxAddr ess) +30
Independentsoft .Webdav.Exchang e.Resource.get_ Mailbox() +176
Independentsoft .Webdav.Exchang e.Resource.GetA ppointments(Boo lean recursive) +31
Independentsoft .Webdav.Exchang e.Resource.GetA ppointments() +27
_Default.getAfs praken() in \\fs11\ao-ict\UserData\ah oeve\Mijn documenten\Visu al Studio 2005\WebSites\W ebSite2\Default .aspx.cs:100
_Default.DropDo wnList1_Selecte dIndexChanged(O bject sender, EventArgs e) in \\fs11\ao-ict\UserData\ah oeve\Mijn documenten\Visu al Studio 2005\WebSites\W ebSite2\Default .aspx.cs:114
System.Web.UI.W ebControls.List Control.OnSelec tedIndexChanged (EventArgs e) +105
System.Web.UI.W ebControls.Drop DownList.RaiseP ostDataChangedE vent() +134
System.Web.UI.W ebControls.Drop DownList.System .Web.UI.IPostBa ckDataHandler.R aisePostDataCha ngedEvent() +7
System.Web.UI.P age.RaiseChange dEvents() +137
System.Web.UI.P age.ProcessRequ estMain(Boolean includeStagesBe foreAsyncPoint, Boolean includeStagesAf terAsyncPoint) +6953
System.Web.UI.P age.ProcessRequ est(Boolean includeStagesBe foreAsyncPoint, Boolean includeStagesAf terAsyncPoint) +154
System.Web.UI.P age.ProcessRequ est() +86
System.Web.UI.P age.ProcessRequ estWithNoAssert (HttpContext context) +18
System.Web.UI.P age.ProcessRequ est(HttpContext context) +49
ASP.default_asp x.ProcessReques t(HttpContext context) in c:\WINDOWS\Micr osoft.NET\Frame work\v2.0.50727 \Temporary ASP.NET Files\website2\ 10a0ed41\15fb0a 6\App_Web_kciwk sky.2.cs:0
System.Web.Call HandlerExecutio nStep.System.We b.HttpApplicati on.IExecutionSt ep.Execute() +154
System.Web.Http Application.Exe cuteStep(IExecu tionStep step, Boolean& completedSynchr onously) +64

Can someone please help me?