Whenever we reboot our 2 dc's one after the other (one is back online before other is rebooted), the exchange server (exh 2013 cu1) stops receiving emails from outside the organization. Users can still send emails to outside world but cannot receive emails from the outside world. It's like the emails are coming through but exchange does not know where to send them.
Any ideas which services need to be restarted to fix this or why this is happening ? If either one of the dc/ad are online it should still function correctly but it does not seem to be the case. What are we missing here ?
PS: after rebooting the os the exchange server just works fine. It's a tricky one.
Sup Doc !