1.7 Set 'Maximum number of recipients - organization level' to '5000'

Information

You can use this setting to control the total number of message recipients. When a message is first composed, the recipients exist in the To:, Cc:, and Bcc: header fields. When the message is submitted for delivery, the message recipients are converted into RCPT TO: entries in the message envelope. A distribution group is counted as a single recipient during message submission.

Rationale:

This setting somewhat limits the impact that a malicious user or a computer with malware can have on the Exchange infrastructure by restricting the number of recipients for any single message.

Solution

To implement the recommended state, execute the following PowerShell cmdlet:

Set-TransportService -Identity 'Server01' -PickupDirectoryMaxRecipientsPerMessage 5000

See Also

https://workbench.cisecurity.org/files/1514

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5

Plugin: Windows

Control ID: 7978133407cc811e28a3602d047cb4852752eb14c7da814bde40f2ac4a20ec69