Filtering IP List

Below is an up-to-date listing of all IP ranges your filtering servers may be deployed on. For convenience, we provide the ranges in three formats to aid in entering them in your chosen firewall:

Last change to IP list: 2021-05-12

IP ranges in bold are required to correctly migrate your service to Hornetsecurity's infrastructure. Please add them as soon as possible to avoid any problems in email routing.

CIDR IP / Network mask First IP ➔ Last IP
209.172.38.64/27 209.172.38.64 / 255.255.255.224 209.172.38.64 ➔ 209.172.38.95
108.163.133.224/27 108.163.133.224 / 255.255.255.224 108.163.133.224 ➔ 108.163.133.255
216.46.2.48/29 216.46.2.48 / 255.255.255.248 216.46.2.48 ➔ 216.46.2.55
216.46.11.224/27 216.46.11.224 / 255.255.255.224 216.46.11.224 ➔ 216.46.11.255
199.27.221.64/27 199.27.221.64 / 255.255.255.224 199.27.221.64 ➔ 199.27.221.95
83.246.65.0/24 83.246.65.0 / 255.255.255.0 83.246.65.1 ➔ 83.246.65.255
173.45.18.0/24 173.45.18.0 / 255.255.255.0 173.45.18.1 ➔ 173.45.18.255
94.100.128.0/20 94.100.128.0 / 255.255.240.0 94.100.128.1 ➔ 94.100.143.255
185.140.204.0/22 185.140.204.0 / 255.255.252.0 185.140.204.1 ➔ 185.140.207.255

Under M365, the IP ranges for the CIDR must be over or equal to /24. The last 2 ranges will need to be replaced with the following entries :

83.246.65.0/24, 94.100.128.0/24, 94.100.129.0/24, 94.100.130.0/24, 94.100.131.0/24, 94.100.132.0/24, 94.100.133.0/24, 94.100.134.0/24, 94.100.135.0/24, 94.100.136.0/24, 94.100.137.0/24, 94.100.138.0/24, 94.100.139.0/24, 94.100.140.0/24, 94.100.141.0/24, 94.100.142.0/24, 94.100.143.0/24, 185.140.207.0/24, 185.140.206.0/24, 185.140.205.0/24, 185.140.204.0/24, 173.45.18.0/24