Some of our services are hosted in the cloud and the IP ranges can change without advance notice. Therefore, we strongly recommend that customers refrain from whitelisting IPs. If you hard code our list of allowed IPs, you may reject some valid responses from our system.
We recommend to use DNS resolution where possible, by resolving your requests to:
Implementing DNS resolution (Domain Name Resolution) has many benefits. One being faster API response times from our system and more resiliency. If one cloud data center is having issues, it will immediately fail over to another data center.