[newbie] smtplib.login()?

[PA]

Hello,

I'm trying to use smtplib.login() to authenticate against a SMTP
server...

server = smtplib.SMTP( 'localhost', 10025 )
server.set_debuglevel(1)
server.login( 'user', 'password' )

send: 'ehlo host.local\r\n'
reply: '250-host.local Hello localhost\r\n'
reply: '250-AUTH LOGIN PLAIN\r\n'
reply: '250 STARTTLS\r\n'
reply: retcode (250); Msg: host.local Hello localhost
AUTH LOGIN PLAIN
STARTTLS
send: 'AUTH PLAIN dXNlcgB1c2VyAHBhc3N3b3Jk\r\n'
reply: '535 Authentication failed\r\n'
reply: retcode (535); Msg: Authentication failed

The above code results in "dXNlcgB1c2VyAHBhc3N3b3Jk" being send to the
server. Which, after decoding, looks like "useruserpassword". Note that
the user name is there twice. Which is going to seriously hamper any
chance of authenticating properly :/

What am I doing wrong? Why is the user name being encoded twice?

Thanks for any help

Cheers