Consider the following scenario. You set the value for "Maximum number of recipients" in the "Transport Settings" to 0. You do this in Exchange Management Console on a Microsoft Exchange Server 2007 server. In this scenario, users cannot send email messages. Additionally, a Non Delivery Report (NDR) is not generated if someone tries to send an email message to one or more recipients.
You expect a NDR to generate a 550 5.5.3 error message which indicates that there are too many recipients.
You can use the Set-TransportConfig cmdlet in Exchange Management Shell to set the MaxRecipientEnvelopeLimit parameter to 0. This setting restricts users to send email messages.
This issue occurs because a NDR message has a recipient that is blocked by the Exchange Server 2007 server. However, a NDR is a system message which should be delivered.
To resolve this problem, install the following update rollup:
2279665 Description of Update Rollup 1 for Exchange Server 2007 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Set-TransportConfig cmdlet, visit the following Microsoft website: