Send vs. Receive Connectors

[Tony Derricott]

I am having trouble wrapping my head around the difference between a Send Connector and a Receive Connector in my Exchange 2010 hybrid server.  Is there a definitive resource online that someone could point me to?

[#2]

One handles inbound mail flow, the other one outbound. The ones created when sing Hybrid make sure that all traffic between on-premises and Exchange Online is encrypted.

You can refer to the TechNet documentation for more details: https://technet.microsoft.com/en-us/library/jj657461(v=exchg.160).aspx

[#3]

The thing I can't really wrap my head around is why this statement in my internal KB:

In order to permit applications to send emails you must set permissions on an exchange receive connector.

[#4]

I'm assuming that's for the scenario where you want to use this application to sent/relay messages via Exchange. Thus, it needs to be allowed on the receive connector first.

[#5]

I think I understand.  So, the Receive Connector - when acting as an SMTP Relay - must receive the message from a separate device before it can relay (send) it on to the Internet.  Right?

[#6 · Accepted solution]

There can be other uses too, but that's kinda the definition, yes.