Exchange Restrict the Number of Recipients per Message

This example restricts the number of recipients per message to 1,000 for your Exchange organization.
Set-TransportConfig -MaxRecipientEnvelopeLimit 1000

This example restricts the number of recipients per message to 300 for messages received through the Receive connector Contoso Receive Connector.

Set-ReceiveConnector -Identity “Contoso Receive Connector” -MaxRecipientsPerMessage 300

This example restricts the number of recipients per message to 200 for messages processed by the Hub Transport server Server01:

Set-TransportServer -Identity “Server01” -PickupDirectoryMaxRecipientsPerMessage 200