Preventing concurrent reading of emails through SwitchYard

Issue

• There is a SwitchYard application with email binding to read the emails which are marked as Unread. This application is deployed in HA environment where active-active setup is running.
  Problem here is both instances are reading same email. The requirement is only any of the instances should read email and other instance should ignore if it is already read by other instance. How to achieve this requirement through SwitchYard ?