Exchange Send connector connections count must be limited.

From MS Exchange 2013 Edge Transport Server Security Technical Implementation Guide

Associated with: CCI-001095

SV-84449r1_rule Exchange Send connector connections count must be limited.

Vulnerability discussion

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 the limit is too high, some domains may use a disproportionate resource share, denying access to other domains. Appropriate tuning reduces the risk of data delay or loss.

Check content

Review the Email Domain Security Plan (EDSP). Determine the value for SMTP Server Maximum Outbound Connections. Open the Exchange Management Shell and enter the following command: Get-TransportService | Select Name, Identity, MaxOutboundConnections If the value of MaxOutboundConnections is not set to 1000, this is a finding. or 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

Update the EDSP. Open the Exchange Management Shell and enter the following command: Set-TransportService -Identity <'IdentityName'> -MaxOutboundConnections 1000 Note: The value must be in quotes. or The value as identified by the EDSP that has obtained a signoff with risk acceptance.

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.