I got this error message on daily basis from One of CAS server. I searched a lot and found that this alert is generating due to FAIL message tracking request . I ran the below command
$msg = get-transportserver | get-messagetrackinglog –start 12/27/2015 –eventid FAIL
$msg | group-object –property Sender,Source | Select-object name,count | sort count –desc | select –first 25 | ft –auto
This cmdlet will result in showing which sender is sending the most messages with message tacking that return a FAIL error event
i got that the sender email address as
MicrosoftExchange329e71ec88ae4615bbc36ab6ce4111@domain.com
When i looked for this object in AD then i found nothing but the type of this object is "msExchExchangeServerRecipient"
i don't find this email address anywhere in EMC. Please let me know what to do with object so that message tracking will get stopped.