Emails sent to Dynamics CRM Users or Queues are not tracked in Dynamics CRM where Forward Mailbox is selected for Incoming and instead gets rejected with below information in Email Router traces:
09/18/2013 09:14:47 : #31826 - Refreshing configuration settings.
09/18/2013 09:14:47 : #1866 - Checking the e-mail message with subject "test 0913" in mailbox xxxxxx@domain.com for delivery to http://<CRMOrgURL>/<OrgName>
09/18/2013 09:14:47 : #60263 - The e-mail message with subject "test 0913" in mailbox xxxxxx@domain.com for delivery to http://<CRMOrgURL>/<OrgName> was rejected. Reason: NoCorrelationMatch.
09/18/2013 09:14:47 : #30906 - Deleting the e-mail message with subject "<subjectname>" in mailbox xxxxxx@domain.com after processing.
09/18/2013 09:14:47 : #20669 - Checking for e-mail messages to process in mailbox xxxxxx@domain.com.
09/18/2013 09:14:47 : #31826 - Refreshing configuration settings.
09/18/2013 09:14:47 : #1866 - Checking the e-mail message with subject "test 0913" in mailbox xxxxxx@domain.com for delivery to http://<CRMOrgURL>/<OrgName>
09/18/2013 09:14:47 : #60263 - The e-mail message with subject "test 0913" in mailbox xxxxxx@domain.com for delivery to http://<CRMOrgURL>/<OrgName> was rejected. Reason: NoCorrelationMatch.
09/18/2013 09:14:47 : #30906 - Deleting the e-mail message with subject "<subjectname>" in mailbox xxxxxx@domain.com after processing.
09/18/2013 09:14:47 : #20669 - Checking for e-mail messages to process in mailbox xxxxxx@domain.com.