# If both messages arrive, both MTAs are working. If not, use the troubleshooting tools and techniques you have already learned to diagnose and fix the problem.<br><br>

{{Admon/important |Backup your VMs!|You MUST perform a '''full backup''' of ALL of your VMs whenever you complete your '''OPS335 labs''' or when working on your '''OPS335 assignments'''. You should be using the dump command, and you should use the Bash shell script that you were adviced to create in order to backup all of your VMs.}}

'''Record steps, commands, and your observations in INVESTIGATION 3 in your OPS335 lab log-book'''