Amazon RDS for Oracle Supports Outbound Network Access Using Custom DNS Servers

In December 2016 we added support for Outbound Network Access from Amazon RDS for Oracle instances. This change enabled your database to communicate with external servers and send emails using the utl_smtp package. Name resolution during outbound network access always used Amazon’s DNS service in your VPC. Today we are adding support for custom DNS servers.
Quelle: aws.amazon.com