Warning! Audit Deprecated
Information
Restrict the IP ranges that can connect to a receive connector.
Recommendation Level: Special Security
ref: https://workbench.cisecurity.org/files/656, pg 51
Solution
Restricting the host IPs or ranges of IPs that can connect to an Edge Receive Connector adds another layer of defense to your Exchange Server. These settings will be organizationally dependent and strict IP ranges may not be practical in larger environments.