Hyland Software does not recommend abruptly stopping a BizTalk application, or the application's host instance, while the BizTalk application is processing messages. Should such an event occur, messages currently being processed by the BizTalk Server can enter the BizTalk Server's Suspended Items queue. Depending on when the application or message processing was stopped, messages can enter the Resumable or Non-resumable queue.
Messages in the Resumable queue can be resumed from the BizTalk Server Administration Console.
Messages in the Non-resumable queue cannot be resumed from the BizTalk Server Administration Console. Messages in the Non-resumable queue are also known as zombie messages. Zombie messages should be manually resubmitted from the original receive location. Using the BizTalk Server Administration Console, remove the original message from the Non-resumable service instances and transfer it to the original receive location.
For more information on zombie messages, see http://msdn.microsoft.com/en-us/library/bb203853(v=bts.70).aspx.