Today we're introducing Dual Delivery, a new feature for Google Message Security that enables a copy of an email to be delivered to two different mail hosts. Dual Delivery provides two benefits. First, it can be used to support a transition to a new email service; second, it can be used as a backup email access point.

Dual Delivery allows an interruption-free transition to a new email solution. By enabling incoming email messages to be copied and sent to two different mailhosts, Dual Delivery gives users the chance to familiarize themselves with a new email platform without disrupting mailflow to the existing system. It also gives IT the chance to learn from user behavior and understand the technical implications of a transition before a full rollout.

Dual Delivery also makes it easier to pilot and transition to Google Apps. By enabling the "Send a copy to Google Apps Gmail" feature of Dual Delivery, you can test Gmail without interrupting current practice. If you choose to switch over to Google Apps, you can enable the "Use Google Apps Gmail" feature in the Administration Console to directly route all of your mail to Gmail without having to manually reroute your MX records.

Dual Delivery can also be used as a secondary email access point. If users are unable to access their primary mailbox for any reason, or if admins want to give users cloud-based remote or mobile email access, Dual Delivery can provide read/write email access through a secondary inbox.

Dual Delivery is now available to Postini customers through the Delivery Manager settings in the Postini Administration Console.

For more information about the Google Postini suite of security and archiving services, visit

Posted by Gopal Shah, Google Postini team

Update 04/05/2010: Dual Delivery is not a tool for migrating historical email or legacy data. It is a tool that makes it easier to transition to a new email system, like Google Apps, by having production email show up in both the new system and the legacy system, allowing you to evaluate both. Please check our Switching from Microsoft Exchange and Switching from Lotus Notes posts, for more information on migrating to Google Apps.