Exchange Connectivity logging must be enabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-221208	SRG-APP-000089	EX16-ED-000070	SV-221208r960879_rule	2024-12-06	2

Description
A connectivity log is a record of the SMTP connection activity of the outbound message delivery queues to the destination mailbox server, smart host, or domain. Connectivity logging is available on Hub Transport servers and Edge Transport servers. By default, connectivity logging is disabled. If events are not recorded, it may be difficult or impossible to determine the root cause of system problems or the unauthorized activities of malicious users. Note: Transport configuration settings apply to the organization/global level of the Exchange SMTP path. By checking and setting them at the Hub server, the setting will apply to both Hub and Edge roles.

Description

A connectivity log is a record of the SMTP connection activity of the outbound message delivery queues to the destination mailbox server, smart host, or domain. Connectivity logging is available on Hub Transport servers and Edge Transport servers. By default, connectivity logging is disabled. If events are not recorded, it may be difficult or impossible to determine the root cause of system problems or the unauthorized activities of malicious users. Note: Transport configuration settings apply to the organization/global level of the Exchange SMTP path. By checking and setting them at the Hub server, the setting will apply to both Hub and Edge roles.

ℹ️ Check
Open the Exchange Management Shell and enter the following command: Get-TransportService \| Select Name, Identity, ConnectivityLogEnabled If the value of "ConnectivityLogEnabled" is not set to "True", this is a finding.

✔️ Fix
Open the Exchange Management Shell and enter the following command: Set-TransportService -Identity <'IdentityName'> -ConnectivityLogEnabled $true Note: The <IdentityName> value must be in single quotes.