Every JumpBox is configured to deliver email just like any other mail server on the internet. Users may run into trouble when using a JumpBox on a local network that is connected to the internet through a cable modem or DSL connection. Some mail servers (like Gmail) may not accept email from hosts using these types of connections. In these cases, your ISP may provide an SMTP relay server that you can configure your JumpBox to use.

To configure your JumpBox to send mail through an SMTP relay server you will have to register your JumpBox and enable shell access then SSH to your JumpBox as the 'admin' user and do the following:

# edit the postfix config file as root
sudo vi /etc/postfix/main.cf
# change the line that says "relayhost = " to say
# "relayhost = smtp.yourcompany.com "
# save the changes then reload the postfix config
sudo postfix reload

This takes care of most user's mail delivery problems but you may still have some recipients where this is not sufficient. Unfortunately, these cases are harder to diagnose and vary widely from recipient to recipient.

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

• DNS entry incorrect or unavailable
• Reverse DNS entry incorrect or unvailable

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:

echo foo | mail -s test user@domain.com

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

Additional Notes

Note: The SMTP Server setting will be configurable through the JumpBox Admin interface in our upcoming JumpBox platform update.
Note: 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.