STIGQter STIGQter: STIG Summary: Microsoft Exchange 2019 Mailbox Server Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 02 Jul 2025:

The Exchange send connector connections count must be limited.

DISA Rule

SV-259679r961155_rule

Vulnerability Number

V-259679

Group Title

SRG-APP-000247

Rule Version

EX19-MB-000126

Severity

CAT III

CCI(s)

Weight

10

Fix Recommendation

Update the EDSP to specify the "MaxOutboundConnections" value.

Open the Exchange Management Shell and enter the following command:

Set-TransportService -Identity <'IdentityName'> -MaxOutboundConnections 1000

Note: The <IdentityName> value must be in quotes.

or

Enter the value as identified by the EDSP that has obtained a signoff with risk acceptance.

Check Contents

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-Object -Property Name, Identity, MaxOutboundConnections

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

or

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

Vulnerability Number

V-259679

Documentable

False

Rule Version

EX19-MB-000126

Severity Override Guidance

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-Object -Property Name, Identity, MaxOutboundConnections

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

or

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

Check Content Reference

M

Target Key

5580