Message size restrictions must be unlimited on Receive connectors.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-33561	Exch-2-705	SV-43981r1_rule	ECSC-1	Low

Description
Email system availability depends in part on best practices strategies for setting tuning configurations. For message size restrictions, multiple places exist to set or override inbound or outbound message size. Failure to control the configuration strategy can result in loss of data or system availability. This setting enables the administrator to control the maximum message size on a receive connector. By applying no limits at the connector level, connectors do not conflict with or prohibit the delivery of messages that would otherwise be permitted by the Exchange configuration at the global (transport) level. Using connectors to control size limits may necessitate the need to apply message size limitations in multiple places, with the potential of introducing conflicts and impediments in the mail flow. Changing this setting at the connector overrides the global one; therefore, if operational needs require it, the connector value may be set lower than that of the global value.

Description

Email system availability depends in part on best practices strategies for setting tuning configurations. For message size restrictions, multiple places exist to set or override inbound or outbound message size. Failure to control the configuration strategy can result in loss of data or system availability. This setting enables the administrator to control the maximum message size on a receive connector. By applying no limits at the connector level, connectors do not conflict with or prohibit the delivery of messages that would otherwise be permitted by the Exchange configuration at the global (transport) level. Using connectors to control size limits may necessitate the need to apply message size limitations in multiple places, with the potential of introducing conflicts and impediments in the mail flow. Changing this setting at the connector overrides the global one; therefore, if operational needs require it, the connector value may be set lower than that of the global value.

STIG	Date
Exchange 2010 Hub Transport Server STIG	2013-01-03

Details

Check Text ( C-41668r2_chk )
Obtain the Email Domain Security Plan (EDSP) and locate the 'Maximum Message Size' value. Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector \| Select Name, Identity, MaxMessageSize Identify Internet-facing connectors on the Edge Transport server. If the value of MaxMessageSize ' is set to ‘unlimited’, this is not a finding. If ' MaxMessageSize' is set to a numeric value, and has signoff and risk acceptance in the EDSP, this is not a finding.

Check Text ( C-41668r2_chk )

Obtain the Email Domain Security Plan (EDSP) and locate the 'Maximum Message Size' value.
Open the Exchange Management Shell and enter the following command:

Get-ReceiveConnector | Select Name, Identity, MaxMessageSize

Identify Internet-facing connectors on the Edge Transport server.

If the value of MaxMessageSize ' is set to ‘unlimited’, this is not a finding.

If ' MaxMessageSize' is set to a numeric value, and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix Text (F-37453r2_fix)
Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'ReceiveConnector'> -MaxMessageSize unlimited If an alternate value is desired, obtain signoff with risk acceptance and document in the EDSP.