Send Connector connections count must be limited.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-33589	Exch-2-760	SV-44009r1_rule	ECSC-1	Low

Description
This setting controls the maximum number of simultaneous outbound connections allowed for a given SMTP Connector, and can be used to throttle the SMTP service if resource constraints warrant it. If the limit is too low, connections may be dropped. If too high, some domains may use a disproportionate resource share, denying access to other domains. Appropriate tuning reduces risk of data delay or loss.

Description

This setting controls the maximum number of simultaneous outbound connections allowed for a given SMTP Connector, and can be used to throttle the SMTP service if resource constraints warrant it. If the limit is too low, connections may be dropped. If too high, some domains may use a disproportionate resource share, denying access to other domains. Appropriate tuning reduces risk of data delay or loss.

STIG	Date
MS Exchange 2010 Edge Transport Server STIG	2019-03-21

Details

Check Text ( C-41695r1_chk )
Obtain the Email Domain Security Plan (EDSP) and locate the value for 'SMTP Server Maximum Outbound Connections'. Open the Exchange Management Shell and enter the following command: Get-TransportServer -Identity <'ServerUnderReview'> \| Select Name, Identity, MaxOutboundConnections If the value of 'MaxOutboundConnections' is set to 1000 this is not a finding. If the value of 'MaxOutboundConnections' is set to a value other than 1000 and has signoff and risk acceptance in the EDSP, this is not a finding.

Check Text ( C-41695r1_chk )

Obtain the Email Domain Security Plan (EDSP) and locate the value for 'SMTP Server Maximum Outbound Connections'.

Open the Exchange Management Shell and enter the following command:

Get-TransportServer -Identity <'ServerUnderReview'> | Select Name, Identity, MaxOutboundConnections

If the value of 'MaxOutboundConnections' is set to 1000 this is not a finding.

If the value of 'MaxOutboundConnections' is set to a value other than 1000 and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix Text (F-37480r1_fix)
Open the Exchange Management Shell and enter the following command: Set-TransportServer -Identity <'ServerUnderReview'> -MaxOutboundConnections 1000. If an alternate value is desired, obtain signoff with risk acceptance and document in the EDSP.