The Exchange Post Office Protocol 3 (POP3) service must be disabled.

POP3 is not approved for use within the DOD. It uses a clear-text-based user name and password and does not support the DOD standard for PKI for email access. User name and password could easily be captured from the network, allowing a malicious user to access other system features. Uninstalling or disabling the service will prevent the use of POP3.

Get-Service -Name MSExchangePop3,MSExchangePOP3BE |Select-Object -Property Name,StartType

If any of the POP3 services StartType is NOT set to "Disabled", this is a finding.

Open the Windows PowerShell in an Elevated Prompt and enter the following commands:

Get-Service -Name MSExchangePop3,MSExchangePOP3BE |ForEach-Object {Set-Service -Name $_.Name -StartupType Disabled}