--- /usr/lib/python2.5/email/generator.py.orig  2008-07-31 21:40:42.000000000 +0300
+++ /usr/lib/python2.5/email/generator.py   2008-12-02 15:08:30.000000000 +0200
@@ -173,6 +173,8 @@
             return
         if not isinstance(payload, basestring):
             raise TypeError('string payload expected: %s' % type(payload))
+        if isinstance(payload, unicode):
+            payload = payload.encode(msg.get_charset().output_charset or 'us-ascii')
         if self._mangle_from_:
             payload = fcre.sub('>From ', payload)
         self._fp.write(payload)