What IP addresses do I need to add to my firewall?
What IP addresses do you use to send requests to my MO or DLR webhook URL?
Can I use a firewall and still receive inbound requests from you?
I am not receiving callbacks to my HTTP server. Why might this be?
If you are restricting inbound traffic, including status reports and delivery receipts, please whitelist the following subnets:
126.96.36.199 -188.8.131.52.78 (184.108.40.206/28)
220.127.116.11 - 18.104.22.168 (22.214.171.124/28)
126.96.36.199 - 188.8.131.52 (184.108.40.206/28)
in your firewall.
Inbound SMS traffic from Nexmo might come from any of the IP addresses included in the referenced subnets.