Index: mcs/class/System.Web/System.Web.UI.WebControls/MailDefinition.cs
===================================================================
--- mcs/class/System.Web/System.Web.UI.WebControls/MailDefinition.cs	(revision 84138)
+++ mcs/class/System.Web/System.Web.UI.WebControls/MailDefinition.cs	(working copy)
@@ -38,6 +38,7 @@
 using System.Web.UI;
 using System.Net.Mail;
 using System.Collections;
+using System.Web.Util;
 
 namespace System.Web.UI.WebControls
 {
@@ -106,9 +107,9 @@
 				if (Path.IsPathRooted (BodyFileName))
 					filePath = BodyFileName;
 				else
-					filePath = Path.Combine (owner.TemplateSourceDirectory, BodyFileName);
+					filePath = UrlUtils.Combine (owner.TemplateSourceDirectory, BodyFileName);
 
-				StreamReader sr = new StreamReader (filePath);
+				StreamReader sr = new StreamReader (owner.OpenFile (filePath));
 				bodyText = sr.ReadToEnd ();
 				sr.Close ();
 			}