<ol><li value="6">Add an '''MX''' record to the forward lookup zone on vm1 so that all incoming mail addressed to the domain is sent to your vm3.</li><li>Restart the service and use the '''dig''' command to confirm that it works.</li><li>Send an email from your '''vm2''' to '''root@yourdomain.org'''</li><li>Confirm that it arrives on your '''vm3''' machine.</li></ol>

When email is sent from either vm, it is addressed from the domain, but receiving MTAs might query why mail sent from vm2 doesn't match the address of the MX record for the domain. This would be a red-flag for potential spam. To avoid this, we can relay all mail sent from vm2 (or any other machine in our network) through vm3 so that it properly appears to come from the mail server that matches the MX record for the domain.