Index: Doc/library/email.mime.rst
===================================================================
--- Doc/library/email.mime.rst	(revision 81585)
+++ Doc/library/email.mime.rst	(working copy)
@@ -191,9 +191,11 @@
    minor type and defaults to :mimetype:`plain`.  *_charset* is the character
    set of the text and is passed as a parameter to the
    :class:`~email.mime.nonmultipart.MIMENonMultipart` constructor; it defaults
-   to ``us-ascii``.  No guessing or encoding is performed on the text data.
+   to ``us-ascii``.  If *_text* is unicode, it is encoded using the
+   *output_charset* of *_charset*, otherwise it is used as-is.
 
    .. versionchanged:: 2.4
-      The previously deprecated *_encoding* argument has been removed.  Encoding
-      happens implicitly based on the *_charset* argument.
+      The previously deprecated *_encoding* argument has been removed.  Content
+      Transfer Encoding now happens happens implicitly based on the *_charset*
+      argument.
 
Index: Doc/library/email.message.rst
===================================================================
--- Doc/library/email.message.rst	(revision 81585)
+++ Doc/library/email.message.rst	(working copy)
@@ -136,9 +136,10 @@
       :mailheader:`Content-Type` header. Anything else will generate a
       :exc:`TypeError`.
 
-      The message will be assumed to be of type :mimetype:`text/\*` encoded with
-      *charset.input_charset*.  It will be converted to *charset.output_charset*
-      and encoded properly, if needed, when generating the plain text
+      The message will be assumed to be of type :mimetype:`text/\*`, with the
+      payload either in unicode or encoded with *charset.input_charset*.
+      It will be encoded or converted to *charset.output_charset*
+      and transfer encoded properly, if needed, when generating the plain text
       representation of the message.  MIME headers (:mailheader:`MIME-Version`,
       :mailheader:`Content-Type`, :mailheader:`Content-Transfer-Encoding`) will
       be added as needed.
Index: Lib/email/test/test_email.py
===================================================================
--- Lib/email/test/test_email.py	(revision 81585)
+++ Lib/email/test/test_email.py	(working copy)
@@ -1045,7 +1045,32 @@
         eq(msg.get_charset().input_charset, 'us-ascii')
         eq(msg['content-type'], 'text/plain; charset="us-ascii"')
 
+    def test_7bit_unicode_input(self):
+        eq = self.assertEqual
+        msg = MIMEText(u'hello there', _charset='us-ascii')
+        eq(msg.get_charset().input_charset, 'us-ascii')
+        eq(msg['content-type'], 'text/plain; charset="us-ascii"')
 
+    def test_7bit_unicode_input_no_charset(self):
+        eq = self.assertEqual
+        msg = MIMEText(u'hello there')
+        eq(msg.get_charset(), 'us-ascii')
+        eq(msg['content-type'], 'text/plain; charset="us-ascii"')
+        self.assertTrue('hello there' in msg.as_string())
+
+    def test_8bit_unicode_input(self):
+        teststr = u'\u043a\u0438\u0440\u0438\u043b\u0438\u0446\u0430'
+        eq = self.assertEqual
+        msg = MIMEText(teststr, _charset='utf-8')
+        eq(msg.get_charset().output_charset, 'utf-8')
+        eq(msg['content-type'], 'text/plain; charset="utf-8"')
+        eq(msg.get_payload(decode=True), teststr.encode('utf-8'))
+
+    def test_8bit_unicode_input_no_charset(self):
+        teststr = u'\u043a\u0438\u0440\u0438\u043b\u0438\u0446\u0430'
+        self.assertRaises(UnicodeEncodeError, MIMEText, teststr)
+
+
 
 # Test complicated multipart/* messages
 class TestMultipart(TestEmailBase):
Index: Lib/email/message.py
===================================================================
--- Lib/email/message.py	(revision 81585)
+++ Lib/email/message.py	(working copy)
@@ -256,6 +256,8 @@
                             charset=charset.get_output_charset())
         else:
             self.set_param('charset', charset.get_output_charset())
+        if isinstance(self._payload, unicode):
+            self._payload = self._payload.encode(charset.output_charset)
         if str(charset) != charset.get_output_charset():
             self._payload = charset.body_encode(self._payload)
         if 'Content-Transfer-Encoding' not in self: