MailFlow issue after installation of Exchange 2019- Hybrid Deployment

muser 21 Reputation points
2021-10-24T17:57:43.817+00:00

We have a hybrid deployment and we migrated from Exchange 2013 to 2019. But we see that emails sent from on prem mailbox is going to EX2019 server, and then to EX 2013 sever and then back to EX2019 server. And then it goes to O365.

We want emails to go to EX2019 server and then to O365 directly. We cant figure out why it is going to EX 2013 server in between.

The send connectors are scoped to EX 2019 servers only. There are no active transport rules.

Please help to figure out why email is going back to 2013 server.

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
7,350 questions
Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
1,886 questions
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2 answers

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  1. Andy David - MVP 141.6K Reputation points MVP
    2021-10-24T18:07:42.08+00:00
  2. KyleXu-MSFT 26,211 Reputation points
    2021-10-25T06:36:14.227+00:00

    @muser

    Could you send a test email with "Tested Email" subject, then use command below to check it? It will could help us know the detailed mail flow and narrow down: 

    Get-TransportService | Get-MessageTrackingLog -Sender user1@domain.com -Recipients user2@domain.com -MessageSubject "Tested Email" -Start 10/24/2021 -End 10/26/2021 | select Timestamp,EventId,Source,ServerHostname | Sort-Object Timestamp

    As AndyDavid said, this phenomenon may related with shadow created. It isn't email sent back to another server, then sent back:
    143352-qa-kyle-14-33-29.png

    143371-qa-kyle-14-34-30.png

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