Default Mail Queue Retention Policy
Email is kept in the mail queue for 30 days, during that time we are attempting to deliver your email to the MX record that is configured for your domain. When mail exceeds 30 days in the queue it is set with a Non Delivery Notification and cannot be recovered.
Expanded Mail Queue Retention Policy
If you require your mail retention to exceed 30 days we have an optional 45-day retention option. Please contact support for more information.