Sending email is severely broken in 1.4.7. The following issues exist:

- get_standard_message used to return a tuple, but now returns a pair.
  client.py still expect it to return a tuple, and still wants to use
  the writer that gets returned.
- smtp_send expects a string; several places pass an email Message
object (client.py, send_message, standard_message). I fixed them by
explicitly invoking str() (as done in several other places; perhaps it
might be better to have smtp_send accept Message objects. Also, I'm not
sure whether str() is the preferred API; there is also .as_string(); the
former defaults to including a unix_from line, the latter doesn't. I
think you don't need the unix_from in SMTP.
- several places create duplicate headers. In email.message, you need to
del a header before setting it anew, otherwise, you get two headers of
the same type. This happens to Content-type and
Content-transfer-encoding in particular.
- several places fail have the content-transfer-encoding match the body;
the encoding defaults to base64 (as the charset is utf-8); still, they
pass completely unquoted payload. I added encode_quopri calls into these
places.