In Ubuntu 2011.04, I want to install an SMTP server for development tests, so I did this:

  • sudo apt-get install postfix
  • Choosed local because I only want to access it from my computer
  • Entered nico (my machine's name, pingable) as mail host name

postfix is running as confirmed by sudo /etc/init.d/postfix status.

PROBLEM: I configured Thunderbird to use my nico as an SMTP server with user nico, but when I send an email a popup appears saying:

Send Message Error. Sending of message failed. The message could not be sent because connecting to SMTP server nico failed. The server may be unavailable or is refusing SMTP connections. Please verify that your SMTP server settings are correct and try again, or contact the server administrator.

Did I forget something? I was following the simple steps from this blog post (I skipped the "further configuration" part).


I typically use 'Internet site with smarthost' for postfix running on my laptop, and specify my company's SMTP server as the smarthost. For a computer that doesn't roam between networks, it would be fine to specify your ISP's SMTP server as the smarthost. If you have a Google account, you could use Google's SMTP as well.

'Internet site' might also work, but it might run afoul of various spam protections, since it will try to reach each recipient's SMTP server directly.

I'm not sure what 'local' means; can you check (netstat -tln) if Postfix is even listening on port 25? If not, Thunderbird won't be able to talk to your Postfix over TCP.

On the Thunderbird side, specify localhost as the SMTP server with no username or password.

  • Thanks! Something is listening to and I receive a different error after following your last line's advice: The mail server responded: 5.1.1 <iewvrowijvw@gmail.com>: Recipient address rejected: gmail.com – Nicolas Raoul Jul 14 '11 at 9:53
  • That points to a possible config issue. Out of curiosity, are you on a Residential IP address? – Thomas Ward Jul 14 '11 at 13:28
  • @Phoenix: I am within a local network, which has a router to the Internet. – Nicolas Raoul Jul 15 '11 at 8:50
  • Now the question is which mail server rejected that email -- your own postfix, or your smarthost? – Marius Gedminas Jul 19 '11 at 19:47

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