MX Guarddog IP Address List

MX Guarddog publishes our IP Addresses for email administrators who wish to perform server hardening for prevention of direct delivery, this information is published for advanced users only.

If you are controlling access to your email server by IP Address, you will need to allow our delivery servers to connect from the following addresses.

Allow access from all addresses to guarantee your email can be delivered. We try and make as few changes to this list as possible... and will inform all impacted customers via email of any upcoming changes.

Active MX Guarddog IP Addresses Phoenix AZ, USAAdded Aug. 2014 AZ, USAAdded Sept. 2015 [*]
Customers joining on or after September 1, 2015 Columbia, CanadaAdded Nov. 2018 [*]
Customers joining on or after November 1, 2018 TX, USAAdded Nov. 2021 [*]
Customers joining on or after November 1, 2021

Resolution By Name

If you have one of those fancy firewalls that can apply rules by using a host name, we got you covered. We publish a list of our active IP addresses under the name

Retired IP Addresses

Retired addresses are no longer being used, if you previously allowed access to any of these addresses you can now safely remove them.

  • - retired November 2021
  • - retired May 2021
  • - retired January 2017
  • - retired October 2014
  • - retired October 2014
  • - retired July 2014
  • - retired March 2014
  • - retired March 2014

  • General General Questions If your email is protected by MX Guarddog, but you're not the postmaster you will find the most relevant questions answered on the general page.
  • Pre-Sales Pre-sales QuestionsIf you are still considering MX Guarddog to protect your organization's email you will find your questions answered on the pre-sales page.
  • Technical Technical QuestionsYou are the the postmaster for your organization, have a question? You will find lots of answers about how things work around here on the tech pages. Things can get quite techie in here, so be sure to wear your pocket protector.
  • Billing Billing QuestionsAre you the bean counter? If you have a question regarding invoices, payments, earning tokens or something else accounting related check for answers on the billing page.