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How Can I Add the Barracuda Email Security Service IP Ranges to O365?

Solution #00007104

Barracuda Email Security Service, using Office 365.


If you are seeing mail from ESS being blocked by O365 because of our IP address then you need to add our IP ranges to your receive connector.

  1. Login to the Office 365 website. Click on Admin, then Exchange.
  2. From the Exchange Admin Center (EAC) click on Protection ->Connection Filtering and you will be able to add the IP ranges.
  3. Click on the + sign to add an IP or range in allow or block IP address. If you will type an invalid IP or subnet, then you will get an error.

Note: The required IP ranges for ESS are - DE Region - UK Region - US Region

Some Customers have reported that you can only add /24 ranges to the O365 setup as well as to some on-prem mail servers.

Below is our US IP ranges broken down into /24 ranges. O365 will only allow a addition of a Class C range (max).

US IP ranges (US region)

DE IP ranges (DE region) - less than a class C

UK IP ranges (UK region) - Less than a class C

Additional Information:

See the following page for more information on configuring this in O365:

Link To This Page: