From JumpBox Documentation Wiki

How can I make my JumpBox send email?

Every JumpBox is configured to deliver email just like any other mail server on the internet. The most common email problem is when DSL or Cable providers block outbound email connections. This is a very common practice and is done to reduce SPAM. This can typically be resolved by finding the SMTP Relay or Outbound Email Relay provided by your ISP and then configuring your JumpBox to use that with the instructions provided below.

Configuring Outbound Email on a 1.1+ JumpBox

The JumpBox Administration Portal can now configure an unauthenticated SMTP/Mail relay for you. Please see the JumpBox Mail Relay Configuration Tutorial.

We do not yet have a convenient way to set up authenticated mail relays. Registered users should be able to manually configure Postfix to do this. See the Postfix Documentation for details.

If you have an older 1.0 JumpBox, see the v1.0 mail relay configuration instructions.

Other Issues

Other environmental issues that are external to the JumpBox may make receiving email difficult, these include:

• Strict SPAM rejection policies falsely rejecting email because:
  • DNS entry incorrect or unavailable
  • Reverse DNS entry incorrect or unavailable
  • Sending host not present in SPF entry
  • No Domain Key
  • Outbound port 25 (SMTP) blocked by ISP
  • Your (JumpBoxes) public IP address is in a block of IP addresses that is thought to send spam, therefore all mail originating from the block of IP addresses is rejected as a policy. Somewhat common for users on home or business DSL or cable accounts.

Testing Mail

To test whether email is getting delivered (either before or after performing the above steps) you can do the following on the command line of the JumpBox:

sendmail -t user@example.com < /etc/services

Check your spam folder to see if it was marked as spam. You can also check the mail.log file and see if the mail was accepted by the remote host, sometimes you will be told in this logfile why a message was rejected:

less /var/log/mail.log

If the logs show Connection timed out then your ISP is most likely blocking your outbound email connections.

Additional Notes

Note: By default, nearly all of the JumpBoxes are not configured to receive email from the internet.

Note: Some applications have Application level SMTP server settings, you may use these if you prefer, but the above method should work across all JumpBoxes.