On Python 2.6.6 it breaks smtplib.SMTP (socket has different method signatures)

[alexandru]

One problem has to do with socket.makefile ... the signature in Python 2.6.6 has both mode and bufsize as optional parameters.

After I fixed that, setting bufsize to a default of -1 (which should be the system's default), then I started to receive "connection quit unexpectedly".

Haven't experimented with a different setting or not or looked at your code really carefully, but breaking the default socket functionality for other protocols is not OK.