Source link: https://social.msdn.microsoft.com/Forums/office/en-US/b14b2184-9ff7-4821-a9eb-eeeff5c3930b/edge-server-support-in-hybrid-deployment-with-centralized-mail-flow?forum=exchangesvrdevelopment
Is the edge server supported supported in a hybrid deployment with centralized mail flow? Yes or No?
I Have configured edge server and bellow is the mail flow status
Mail from On-prem mailbox to on cloud mailbox: Success
Mail from On-Cloud to On-Prem: Success
Mail from external recipient to on cloud: Success
Mail from on cloud to external recipient: Fail
For the last scenario my edge server is rejecting internet bound messages from EOP with the error 5188.8.131.52 unable to relay recipient in non-accepted domain.
I then gave the ms-Exch-SMTP-Accept-Any-Recipient extended rights on the edge server receive connector. This time the mails went trough EOP but then got stuck on the edge server where now I am receiving the error A matching connector cannot be found to route the external recipient.
I even changed the domain to * in the edge sync connector but after doing so all the emails in queue got flushed with an NDR message, interestingly those NDR's were not delivered to the cloud user where the mail had originated from