STIGViewer Support

Exchange Receive connectors must control the number of recipients per message.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-221229EX16-ED-000300SV-221229r961155_ruleCCI-001095medium
Description
Email system availability depends in part on best practice strategies for setting tuning configurations. This configuration controls the maximum number of recipients who will receive a copy of a message at one time. This tunable value is related to throughput capacity and can enable the ability to optimize message delivery. Note: There are two types of default Receive connecters: "Client Servername" accepts SMTP connections from all non-MAPI clients, such as POP and IMAP. As POP and IMAP are not authorized for use in DoD, these should not be present. Their default value for MaxRecipientsPerMessage is 200. IMAP Secure is not restricted and may be configured. "Default Servername" accepts connections from other mailbox servers and any Edge Transport servers. Their default value for MaxRecipientsPerMessage is 5000.
STIGDate
Microsoft Exchange 2016 Edge Transport Server Security Technical Implementation Guide2024-12-06

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (2) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

CAP-02Resource Priority
0.50
CAP-03Capacity Planning
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (13) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-17(10)Authenticate Remote Commands
1.00
AC-17(9)Disconnect or Disable Access
1.00
AC-3Access Enforcement
1.00
AC-4Information Flow Enforcement
1.00
AU-3Content of Audit Records
1.00
CM-6Configuration Settings
1.00
CM-7Least Functionality
1.00
CM-7(2)Prevent Program Execution
1.00
SC-47Alternate Communications Paths
1.00
SC-5Denial-of-service Protection
1.00

+3 more (top 10 by confidence shown)

CCI1 mapping
NIST CSF 2.00 mappings

No source states a mapping between these directly.

Also reachable in 4 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

Details

Check Text (C-221229r961155_chk)

Review the Email Domain Security Plan (EDSP). Determine the Maximum Recipients per Message value. Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector | Select Name, Identity, MaxRecipientsPerMessage For each receive connector, if the value of "MaxRecipientsPerMessage" is not set to "5000", this is a finding. or If the value of "MaxRecipientsPerMessage" is set to a value other than "5000" and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix Text (F-22933r411814_fix)

Update the EDSP to reflect the Maximum Recipients per Message value. Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'IdentityName'> -MaxRecipientsPerMessage 5000 Note: The <IdentityName> value must be in single quotes. or The value as identified by the EDSP that has obtained a signoff with risk acceptance. Repeat the procedure for each receive connector.