Exchange must use encryption for RPC client access.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-228415SRG-APP-000014EX16-MB-002900SV-228415r879519_rule2023-12-182
Description
This setting controls whether client machines are forced to use secure channels to communicate with the server. If this feature is enabled, clients will only be able to communicate with the server over secure communication channels. Failure to require secure connections to the client access server increases the potential for unintended eavesdropping or data loss.
ℹ️ Check
Open the Exchange Management Shell and enter the following command: Get-RpcClientAccess | Select Server, Name, EncryptionRequired If the value of "EncryptionRequired" is not set to "True", this is a finding.
✔️ Fix
Open the Exchange Management Shell and enter the following command: Set-RpcClientAccess -Server <ServerName> -EncryptionRequired $true