LTools.Office.MSExchangeApp app = LTools.Office.MSExchangeApp.InitSvc(wf, Microsoft.Exchange.WebServices.Data.ExchangeVersion.Exchange2013_SP1, "server url", "login", "pass", "domain");
List<LTools.Office.Model.OMailMessage> msg = app.ReadMail("Inbox", true, false, 10);
app.MarkMail(mag[0], LTools.Office.Model.OMailMarkTypes.IMPORTANCE_HIGH);