Postfix on linux not sending mail

For some reason my server has stopped sending mail, and I am not sure why. I am running Debian 5.0 with postfix. I remember setting it up using apt-get, and it worked fine.

Is there a config file that I need to update? Can I send a test email from the shell?

From serverfault Zed Said

• Sending a test email from the shell can be accomplished with:

  echo "test-body" | mailx -s "test-subject" username@example.com

  You might need to apt-get mailx or so.

  I'm not familiar with postfix, but maybe there's a log file in /var/log you can look at, or check /var/log/daemon.log.

  From ultrasawblade

• You should check your logfiles

  /var/log/mail.log
  /var/log/mail.err
  /var/log/daemon.log
  

  It would be good to know if your mails are queued:

  mailq
  

  If there are mails in your queue try:

  sendmail -q
  

  Check your postfix service status:

  /etc/init.d/postfix status
  

  Please check your postfix configuration:

  postfix check
  

  Edit:

  Please check your dns setup:

  nslookup www.google.de
  

  Please check if you are able to ping any of the destination domains:

  ping www.google.de
  

  Zed Said : Thanks, I see TONS of emails in the queue. I am using google apps, and see these errors in the queue: delivery temporarily suspended: connect to ASPMX3.GOOGLEMAIL.com[72.14.213.27]:25: No route to host (delivery temporarily suspended: connect to ASPMX4.GOOGLEMAIL.com[209.85.229.27]:25: Connection timed out)

  Andreas Rehm : Please check if your dns setup works - I've edited my post.
  From Andreas Rehm