By looking through the smtplib module code I think I've found a
potential issue in the SSLFakeFile class code since there's a while loop
which is supposed to be stopped only when the "\n" character is encountered:

        def readline(self):
            str = ""
            chr = None
            while chr != "\n":
                chr = self.sslobj.read(1)
                str += chr
            return str


The patch in attachment just adds a break statement to prevent the while
loop to hang forever in case the "\n" character is never encountered.

As of 2.6 the smtplib uses the ssl module, until 2.5 it uses _ssl, I
*think* that this issue would bring an Exception on 2.5 while on 2.6
would return a zero length string:
"""
def read(self, len=1024):

        """Read up to LEN bytes and return them.
        Return zero-length string on EOF."""

        return self._sslobj.read(len)
"""

wich would fulfill the "if not chr:"

ssl.SSLSocket.read() says: Return zero-length string on EOF.  So, I'm
going to apply this patch.  Applied in rev 61656.