Troubleshoot Exchange Server Error 451 4.4.0

The Exchange server error 4514.4.0 problem occurs due to the following two reasons.

• Sending emails to specific remote domains
• Sending emails to all remote domains

Scenario 1

If the Exchange server error 4514.4.0 problem occurs when you send emails to specific remote domains, refer to the step-by-step guidelines provided below.

• Go to the MX Record lookup tool to check the IP address of the affected remote domain’s MX record, i.e., mail server.
• You have to create a new send connector for the affected domain as per the steps given here.
• Launch the New Send Connector window and select the Address Space option on the left panel.
• Choose the affected remote domain from the list. If the affected remote domain is not available in the list, click the Add icon and add the affected remote domain.
• After you click the Network Setting option on the left panel, select the radio button next to the ‘Route mail through the following smart host’ option.
• Click the Add icon, select the radio button beside the IP Address option, and enter the IP address of the MX record.
• Click the OK -> Network Settings -> Configure smart host authentication settings on the left panel.
• Select the radio button next to the None option and click the Next option.
• For the rest of the settings, use the default value. Check if the Exchange server error 4514.4.0 problem has been resolved.

Scenario 2

If the Exchange server error 4514.4.0 problem occurs at the time of sending an email to all remote domains, carry out the solution given here.