Error logging exception:

System.Web.HttpException (0x80004005): This is an invalid webresource request.
   at System.Web.Handlers.AssemblyResourceLoader.System.Web.IHttpHandler.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Error:

System.FormatException: The specified string is not in the form required for an e-mail address.
   at System.Net.Mail.MailAddressParser.ReadCfwsAndThrowIfIncomplete(String data, Int32 index)
   at System.Net.Mail.MailAddressParser.ParseAddress(String data, Boolean expectMultipleAddresses, Int32& index)
   at System.Net.Mail.MailAddressParser.ParseMultipleAddresses(String data)
   at System.Net.Mail.MailAddressCollection.ParseValue(String addresses)
   at System.Net.Mail.Message..ctor(String from, String to)
   at System.Net.Mail.MailMessage..ctor(String from, String to)
   at ASP.global_asax.Application_Error(Object sender, EventArgs e)