Exchange 2010: Allow SMTP relaying

Some old fashioned programs require to send mail without any form of authentication.
I will show you how to set up a SMTP relay with Exchange 2010 for all mail coming from a specific host.

Topology:
- fim-dc: 192.168.6.1
- fim-exchange: 192.168.6.100 (Exchange 2010 installed)

We want to allow all mail sent from fim-dc to be accepted like any other "normal" mail.

Here are the steps to achieve this goal:

- launch the Exchange management console

- in the Server Configuration > Hub Transport, create a new Receive connector

- give the receive connector a name:


- if you want to do any ip filtering on the receiving interface, fill the correct ip (here we would only allow mail to be received on the 192.168.6.100 ip)


- define the remote ip from where we want to relay all SMTP traffic (in our case: 192.168.6.1)


- then click on "New", a powershell command is run. The receive connector is now created.


- we now have to disable all authentication on that receive connector: Right click on its name > propreties > Authentication, and then uncheck all the boxes.


- then we have to grant the Anonymous users the right to connect, in order to send mail to the transport hub.


- done!

Now any mail coming from 192.168.6.1 to 192.168.6.100 will be relayed using SMTP relaying in Exchange 2010!