Newly created users are unable to receive mails from outside network. They were able to receive mails from internally.
Root Cause Analysis
Communication problem between Exchange Hub Transport Server and Edge Transport server . User account called ESRA Bootstrap was expired
1) Create a new subscription file on the Edge server: ( New-EdgeSubscription -file “c:\subscription.xml”)
2) On Hub server open up Exchange System Manager and add the new subscription: Organization Configuration> Hub Transport> Create New Edge Subscription.
3) Start-EdgeSynchronization ( from Hub Transport Server)
4) Test-EdgeSynchronization ( From Hub Transport Server )
After this user’s start getting emails from outside.