Exchange must limit the Receive connector timeout.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-259630	SRG-APP-000295	EX19-ED-000159	SV-259630r1043182_rule	2024-12-06	2

Description
Email system availability depends in part on best practices strategies for setting tuning. This configuration controls the number of idle minutes before the connection is dropped. It works in conjunction with the Maximum Inbound Connections Count setting.

ℹ️ Check
Review the Email Domain Security Plan (EDSP), or Organizations applicable documentation. Determine the connection Timeout value. Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector \| Select-Object -Property Name, Identity, ConnectionTimeout For each Receive connector, if the value of "ConnectionTimeout" is not set to "00:05:00", this is a finding. If "ConnectionTimeout" is set to another value other than "00:05:00" and has signoff and risk acceptance in the EDSP, this is not a finding.

ℹ️ Check

Review the Email Domain Security Plan (EDSP), or Organizations applicable documentation. Determine the connection Timeout value. Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector | Select-Object -Property Name, Identity, ConnectionTimeout For each Receive connector, if the value of "ConnectionTimeout" is not set to "00:05:00", this is a finding. If "ConnectionTimeout" is set to another value other than "00:05:00" and has signoff and risk acceptance in the EDSP, this is not a finding.

✔️ Fix
Update the EDSP, or the applicable documentation. Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'IdentityName'> -ConnectionTimeout 00:05:00 Note: The <IdentityName> value must be in quotes. or The value as identified by the EDSP that has obtained a signoff with risk acceptance. Repeat the procedures for each Receive connector.