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SpamHero is a great solution for customers using Microsoft 365 (or Exchange Online or Office 365) that want better spam filtering.

Basic configuration

If your domain is already using Microsoft 365, our provisioning system will attempt to do the first step for you, but it is a good idea to verify your settings.

Before getting started, take a look at the

The first couple of steps are on the Mail delivery host page (

  1. Login to your SpamHero control panel and go to Settings > Mail delivery host ( and enter the hostname from the MX record that Microsoft assigns to your domain.

    It will look something like this: 
  2. On the Mail delivery host page, enable the Mail host will only accept email from specific IPs or on a specified port option, and then click on View IP addresses and grab the list of IPs that will be used to deliver emails from SpamHero (save this list of IPs for step 4).

  3. In your DNS provider's control panel, switch the MX records for your domain to the ones assigned by SpamHero (and remove all other MX records). Your domain's MX records can be found on the Mail delivery host page ( in the Required MX settings section of the page (scroll down).
  4. Update the Connection Filter Policy in the Microsoft 365 control panel to ensure that mail is always delivered from SpamHero IPs without delay. See: Configuring Microsoft 365 for fast, reliable deliveries


Additional resources

Last updated September 25, 2023