i just introduced an exchange 2016 server to our existing 2010 environment, the installation and configuration went well, but now i'm having a problem on sending and receiving an email from/to 2010 and 2016, i can send an email to external from both 2010 and 2016 but i cant send between both internal servers, below is the configuration of the receive connectors on 2010 and 2016 respectively.

Exchange 2010 Receive Connector

Exchange 2010 Receive Connector

Best Regards.

2 Answers 2


Exchange 2010 has a bug where the default receive connectors which allow incoming mail from must have the IP address of any newer Exchange server explicitly added to the whitelist.


Primary reason for mail flow failure at this stage is a restriction on the scope, which is allowing connections from a set of external IP addresses only. Therefore I would start there.

The emails should be in a queue - the queue viewer can also give you an indication of the reason for the email delivery failure.

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