Postfix hangs when sending email

If I try to send an email as follows, the process hangs and nothing happens:

>>> from django.core.management import setup_environ
>>> from cube import settings
>>> setup_environ(settings)
'cube'
>>> from django.core.mail import send_mail
>>> send_mail('Subject', 'Message', 'sender@domain.com', ['recepient@domain.com'], fail_silently=False)

However, doing telnet to port 25 works just fine

$ telnet localhost 25
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
^]

telnet> 

and here's this just in case

$ netstat -a | grep :smtp
tcp        0      0 *:smtp                  *:*                     LISTEN     
tcp        0      0 localhost:smtp          localhost:44932         ESTABLISHED
tcp        0      0 localhost:44932         localhost:smtp          ESTABLISHED
tcp        0      0 localhost:smtp          localhost:60964         ESTABLISHED
tcp        0      0 localhost:60964         localhost:smtp          ESTABLISHED
tcp     开发者_JS百科   0      0 localhost:37247         localhost:smtp          FIN_WAIT2  
tcp        1      0 localhost:smtp          localhost:37247         CLOSE_WAIT 
tcp        9      0 localhost:smtp          localhost:37245         CLOSE_WAIT 

I run Ubuntu 10.04 and Python 2.6.5

I don't know where to look next to figure out what's wrong. Please help me. Thank you.

Your mail server isn't working fine. When you connect to it using telnet, you should see a welcome message along the lines of:

220 your.server.name ESMTP Postfix

(You can check the greeting that you should be seeing by running postconf smtpd_banner.)

You don't get that, so the mail server isn't running properly. send_mail is probably hanging waiting for that initial message.

Restart Postfix, and look in the /var/log/mail.* log files; there may be a clue in there as to why it's not working.