When the email messages are showing as ‘Pending Send’ in CRM, and opening the message shows. The message has not yet been submitted for delivery. For more information, see help. If you look in the services for the email router, you will see it has stopped. Starting the email router, the service will start then stop.
Navigate to: C:\Program Files\Microsoft CRM Email\Service
Find the file: Microsoft.Crm.Tools.EmailAgent.SystemState.xml
Rename or delete the file. Then start the CRM Email Router Service.