I recently updated Exchange Server 2013 CU3 to Exchange Server 2013 SP1. The update seemed to go smoothly however I discovered that external emails were not flowing. Oddly enough outbound emails worked just fine.

Symptoms

  • No inbound email being processed by Exchange 2013 SP1.
  • You also notice the following loged in the Application Event Logs:
    Source: MSExchangeFrontEndTransport 
    Event ID: 7012
    Description: The service state for frontend transport is inconsistent. Current state – Inactive. Expected state – Active.

Cause

Transport agent failure caused email to stop being processed. I later found the following post regarding the issue: [E2013][TA] Exchange 2013 SP1 transport agent “type not found” issue

Resolution

To resolved this issue (in my case). I needed to restart the Microsoft Exchange Frontend Transport service.  *note* restarting the transport service alone will not solve this.

Conclusion

  • Avoid updating service packs for several months until all the bugs are worked out and known
  • If you are updating, be prepared to face the unknown

 

Microsoft has just officially confirmed the existence of this issues in Exchange Server 2013 SP1: http://support.microsoft.com/kb/2938053

I must note that I am not using any third-party agents.