Index: smtplib.py
===================================================================
--- smtplib.py	(revision 1137)
+++ smtplib.py	(working copy)
@@ -325,7 +325,14 @@
             print>>stderr, 'send:', repr(str)
         if hasattr(self, 'sock') and self.sock:
             try:
-                self.sock.sendall(str)
+                while True:
+                    chunk = str[:0xffff]
+                    str = str[0xffff:]
+                    while chunk:
+                        sent = self.sock.send(chunk)
+                        chunk = chunk[sent:]
+                    if not str:
+                        break
             except socket.error:
                 self.close()
                 raise SMTPServerDisconnected('Server not connected')