SQL Server Database Mail failing to send emails with error Sender address rejected: Access denied The environment is a 2 node 2008 SQL Cluster.  The first node was running fine but after failover to the second node Database Mail no longer can send emails.  I am using Basic authentication.

The full error message is: The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 0 (2012-04-10T15:26:56). Exception Message: Cannot send mails to mail server. (Transaction failed. The server response was: 5.7.1 : Sender address rejected: Access denied). )

This appears to be a SMTP issue but I have validated it is not by writing a vbscript with CDO using the same credentials as Database Mail configuration and the emails go through fine on the same box.

I have recreated the Database Mail account on the second node just to make sure the credentials are correct but that didn't fix the problem.

Does anyone know how to get this working again?
Perhaps the IP of your second node is not allowed to relay.