Exchange receive connectors must control the number of recipients chunked on a single message.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-259605	EX19-ED-000118	SV-259605r961155_rule		Medium

Description
Email system availability depends in part on best practice strategies for setting tuning configurations. For message size restrictions, multiple places exist to set or override inbound or outbound message size. Failure to control the configuration strategy can result in loss of data or system availability. This setting enables the administrator to enable "chunking" on received messages as they arrive at the domain. This is done so large message bodies can be relayed by the remote sender to the Receive connector in multiple, smaller chunks.

Description

Email system availability depends in part on best practice strategies for setting tuning configurations. For message size restrictions, multiple places exist to set or override inbound or outbound message size. Failure to control the configuration strategy can result in loss of data or system availability. This setting enables the administrator to enable "chunking" on received messages as they arrive at the domain. This is done so large message bodies can be relayed by the remote sender to the Receive connector in multiple, smaller chunks.

STIG	Date
Microsoft Exchange 2019 Edge Server Security Technical Implementation Guide	2024-06-10

Details

Check Text ( C-63344r942127_chk )
Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector \| Select-Object -Property Name, Identity, ChunkingEnabled For each receive connector, if the value of "ChunkingEnabled" is not set to "True", this is a finding.

Fix Text (F-63252r942128_fix)
Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'IdentityName'> -ChunkingEnabled $true Note: The value must be in quotes. Repeat the procedure for each receive connector.