Non-delivery report when you send an e-mail message to a remote Exchange 2007 organization that has the IP Block list enabled: "550 5.7.1 External client does not have permissions to submit to this server"

When you send an e-mail message to a remote Microsoft Exchange Server 2007 organization, the e-mail message may not be delivered as expected. Additionally, you may receive a non-delivery report (NDR) that resembles the following:This issue occurs if the IP Block list is enabled on the Edge server in the receiving Exchange 2007 organization.

Exchange Server 2007 provides an IP address-blocking feature that is based on the sender's reputation. The issue that is described in the "Symptoms" section occurs if your mail server's IP address is included on the IP Block list of the Edge server for the receiving Exchange 2007 organization.

To resolve this issue, contact the receiving organization. Then, request that it add your mail server's IP address to the IP Allow list of the Exchange 2007 server that has IP address-blocking enabled. This action will make sure that anti-spam filters are bypassed for e-mail messages that are sent from your mail server.

Note For the administrator of the receiving organization to trust your organization, he or she must make sure that e-mail messages from your organization do not include spam, malware, or other unsuitable content.

For more information about how to configure the IP Allow list and the IP Block list, visit the following Microsoft TechNet Web site:

For more information about this issue, visit the following Microsoft TechNet Web site: