I am trying to track down a issue for past of couple of days and couldn't nail it down. Help is much is appreciated!! We have a CRM 2011 on premise setup with Update Rollup 17 on the server. I have seen in some scenarios that some of the E-mails are not tracked in CRM. Inbound and outbound E-mails are set to go through E-mail router for all users and Email is tracked with Email token. When I looked at Event viewer of e-mail router server, I noticed following error.

#27938 - An error occurred while checking for e-mail messages to process in mailbox xxxxx@xxx.com. Microsoft.Crm.Tools.Email.Providers.EmailException: Error: The specified object was not found in the store.

   at Microsoft.Crm.Tools.Email.Providers.ExchangeWSConnector.LogEwsResponseErrorWarning(String message, ResponseClassType responseClassType)

   at Microsoft.Crm.Tools.Email.Providers.ExchangeWSConnector.RetrieveMessage(ArrayList ids, Int32 index, ServiceLogger serviceLogger)

   at Microsoft.Crm.Tools.Email.Providers.ExchangePollingMailboxProvider.RetrieveNextMessageInternal()

   at Microsoft.Crm.Tools.Email.Providers.CrmPollingMailboxProvider.RetrieveNextMessage()

   at Microsoft.Crm.Tools.Email.Providers.CrmPollingMailboxProvider.Run()

I am stuck. Any help is much appreciated!