New Servers to Whitelist

MxToolbox uses a set of servers as part of our monitoring products.  These perform the heavy lifting like making SMTP calls to your servers or checking your DNS records.  If you are using MxToolbox monitoring for any system behind a firewall, you will probably need to whitelist our servers to get accurate monitoring service.

The current list of keeper IP addresses to whitelist is:

  • 64.20.227.128/28
  • 54.84.234.24
  • 54.164.124.219
  • 54.88.4.135

Please contact Support@MxToolbox.com if you have any issues.