The API endpoints supported by ENS2 are listed in this topic.

When using cloud ENS servers, you must ensure that the ENS is accessible from the Exchange or Office 365 environment. The inbound IP addresses must be whitelisted to permit the ENS traffic into Exchange or Office 365. The IP address is selected based on the region the ENS is hosted in. The following table describes the Exchange server IP whitelisting requirements.

Table 1. Exchange Server IP Whitelisting Requirements
Location API Endpoint ENS Outbound to Exchange Inbound
North America

Asia Pacific

European Union (EU)

United Kingdom (UK)

For information on the architecture design and functionality of ENS2, see Architecture Overview.


The Exchange outbound connections are required to Cloud ENS and CNS. VMware leverages the public cloud providers for the greatest availability of services and cannot provide a static list of IPs. If there is a requirement to limit the outbound connectivity, the following hostnames can be used. For ENS use,,, and (based on region in which the ENS is used) and for CNS use

The outbound IP addresses must be whitelisted from the Microsoft Exchange client access rules (including Office 365) and any other firewall. This permits the outbound communication from the Exchange server into the ENS server. You need not whitelist SEG IP addresses as all outbound connections from the Exchange server is going to the ENS server and not to the SEG EWS proxy.