Link: http://exchangeserverpro.com/exchange-2010-message-tracking-event-ids-powershell/
[PS] C:\>Get-MessageTrackingLog -ResultSize Unlimited | Group-Object -Property:EventId | Sort-Object Count -Desc | Select Name,Count Name Count ---- ----- RECEIVE 58679 DELIVER 47496 NOTIFYMAPI 20812 SUBMIT 20806 SEND 19863 RESUBMIT 8679 HAREDIRECT 6826 TRANSFER 351 DSN 96 FAIL 95 SUBMITDEFER 6 BADMAIL 2