mail from two exchange 2013 CU13 sending message from internal to internal Exchange 2016 CU3 sometimes mail gets stuck with message in title. It is the same situation as mentioned on blog http://exchangeserverpro.com/september-2016-updates-exchange-server-20162013/ where
We found out when “user A” is sending e-mail to ‘distribution group A’ !and! to himself,(Where “User A” is also member of “Distribution group A) e-mail will be delivered but gets stuck in queue with error
how to fix?
an event log error 4999 MSExchange Common occurs around the same time:
Watson report about to be sent for process id: 7172, with parameters: E12, c-RTL-AMD64, 15.00.1210.003, edgetransport, M.Exchange.Transport, CheckIfSentFromHubAndReceivedByHub, FormatException, 63718994, 15.00.1210.002.
ErrorReportingEnabled: True
rebooting the server did not help.
doing windows updates did not help.
updating to CU14 did not help.
updating to .net 4.6.1 did not help.