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 allow the ENS traffic into Exchange or Office 365. Based on the security policies applied to the outgoing traffic from Exchange, it might be necessary to whitelist the outbound IP addresses. 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 Exchange Outbound to ENS Inbound
North America

Asia Pacific

European Union (EU)

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

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