Bogus WHM reverse DNS, TLS, and Transaction Time problems testing a site using MX Toolbox Email Health

MX Toolbox might report bogus problems with testing a fully protected WHM domain. These warnings will take the forms of the following:

3 Problems

  • Reverse DNS does not match SMTP Banner
  • Warning – Does not support TLS.
  • 15.290 seconds – Not good! on Transaction Time

In fact, all three are bogus. WHM has a protection level called “Delay SMTP connections” but you can bypass it by adding at least the following two IP addresses to Greylisting bypass:


What happens is MX Toolbox does an SMTP connection test, gets a timeout, and doesn’t quite know how to handle it producing these bogus problems.

To see if your fix worked, add those IP addresses and do email health again.


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