Index: Doc/includes/email-simple.py
===================================================================
--- Doc/includes/email-simple.py	(révision 67201)
+++ Doc/includes/email-simple.py	(copie de travail)
@@ -6,10 +6,10 @@
 
 # Open a plain text file for reading.  For this example, assume that
 # the text file contains only ASCII characters.
-fp = open(textfile, 'rb')
-# Create a text/plain message
-msg = MIMEText(fp.read())
-fp.close()
+charset = 'ASCII'
+with open(textfile, 'r', encoding=charset) as fp:
+    # Create a text/plain message
+    msg = MIMEText(fp.read(), 'plain', charset)
 
 # me == the sender's email address
 # you == the recipient's email address
Index: Lib/email/message.py
===================================================================
--- Lib/email/message.py	(révision 67201)
+++ Lib/email/message.py	(copie de travail)
@@ -229,6 +229,8 @@
         Optional charset sets the message's default character set.  See
         set_charset() for details.
         """
+        if not isinstance(payload, str):
+            raise TypeError('Expected str, got %s' % type(payload))
         self._payload = payload
         if charset is not None:
             self.set_charset(charset)