Thanks for recommending our DNS tools, we greatly appreciate it. We also wanted to let you know that our Monitoring tool can send you alerts if your MX records change, are removed or expire. Our monitoring tool can also send alerts for email server Up/Down or Blacklists issues. You can find more details out about this free tool here: http://mxtoolbox.com/services_servermonitoring.aspx

Thanks,

@mxtoolbox