Exch2016 Send Connector Local Loop Detected

Question

_{Tuesday, June 21, 2016 5:28 PM}

Migrating from Exchange 2010 to Exchange 2016. Exch4016 server is routing all email back to Exch4010 server currently, everything is flowing fine in that setup.

Went to change the send connector on the Exch4016 machine so that mail would no longer send out via the Exch4010 server.  Source server on the default send connector was changed from Exch4010 server name to the Exch4016 server name.  Once that was done no outgoing mail is flowing.  Going into the queue the 'last error' is  'A local loop was detected'.  As soon as the source server was put back to the Exch4010 server mail started flowing again.  

We are using a smarthost for outgoing mail and the new IP addresses for the servers were already entered on the spam filtering service.

All replies (1)

_{Wednesday, June 22, 2016 9:26 AM ✅Answered}

Hi Jody,

For your question, I want to confirm:

1. Do you deploy Edge server in your environment?
2. Is there additional send connector?

We can add new Exchange 2016 into source server in sender connector, however don't point to local address. Because send connectors should only point to an external host, and place as organization settings. Please run below command to list:
Get-SendConnector | FL Idenity,AddressSpaces,SourceTransportServers,Enabled

You can remove the Exchange 2016 from AddressSpaces in each connector, also use below command to add it to source server:
Set-SendConnector <Identity of send connector> -SourceTransportServers HUB2010,Exchange2016

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Allen Wang
TechNet Community Support