Assembly: Microsoft.Office.InfoPath (in Microsoft.Office.InfoPath.dll)
The MailEnvelope object can be used only with the editing window types; if used with a designing window type, it will raise an exception. It will also raise an exception if no form is open in the form area.
This member can be accessed only by forms running in the same domain as the currently open form, or by forms that have been granted cross-domain permissions.
This type or member can be accessed only from code running in forms opened in Microsoft InfoPath Filler.