MXTRAX is a system to monitor the functionality of entire email systems. In contrast to standard monitors that test for open ports or running processes, MXTRAX sends live test messages through the entire email system to measure processing latency and look for backlogs or delivery failures along the way. MXTRAX notifies the user if at least one of the email addresses is not returning email tests on time.

For more info, visit: https://github.com/Citon/mxtrax/wiki/MXTRAX-wiki