Send Connector connections count must be limited.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
Exch-HB-214	Exch-HB-214	Exch-HB-214_rule		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. Note: Transport configuration settings apply to the organization/global level of Exchange by checking and setting them at the Hub server the setting will apply to both Hub and Edge roles.

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. Note: Transport configuration settings apply to the organization/global level of Exchange by checking and setting them at the Hub server the setting will apply to both Hub and Edge roles.

STIG	Date
Microsoft Exchange 2010 Hub Transport Server Role	2012-05-31

Details

Check Text ( C-_chk )
Obtain the Email Domain Security Plan (EDSP) and locate the value for "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 or less, this is not a finding. If the value of "MaxOutboundConnections" is set to more than 1000, and has signoff and risk acceptance in the EDSP, this is not a finding.

Check Text ( C-_chk )

Obtain the Email Domain Security Plan (EDSP) and locate the value for "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 or less, this is not a finding.

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

Fix Text (F-_fix)
Open the Exchange Management Shell and enter the following command. Set-TransportServer -Identity <'ServerUnderReview'> -MaxOutboundConnections 1000 or other value as identified by the Email Domain Security Plan.