In every environment you may have different devices and appliances that may need to send email or notifications. This guide will go thru the process on how to configure your Linux server with Postfix Mail Transfer Agent. Thru the guide I will use Ubuntu as the Linux distribution for the demo.
1. Make sure to configure Exchange to accept email for relay. Check this post for how to configure Exchange 2013 to relay your mail for appliances.
2. Install all the required packages. ex. sudo apt-get install mailutils
3. During the installation it will ask to configure the basic settings for Postfix. Select Satellite system. This mean your linux system is not managing email it is just sending it out.
4. Type your domain fqdn in the next screen. Ex. domain.com
5. Type the IP address of your Exchange 2013 server hosting the receive connector. Ex. 111.222.333.123
6. After the installation finishes. You need to reconfigure Postfix. To reconfigure Postfix execute the following command: sudo dpk-reconfigure postfix
7. Press OK.
8 . Click Satellite system –> TAB –> OK
9. validate the domain is correct. Press OK.
10. Check that you have the correct IP Address for the Exchange Server.
11.Type the email address for the administrator
12. Erase all the destinations. This will force all the email to go out and not accept any email.
13. In the Force Synchronous updates on mail queue, select Yes
14. Because we are only sending email out, tab to OK.
15. Leave the mailbox size on 0.
16. Leave the local address extension + and tab to OK.
17. Tab to ipv4 and then select OK.
18. After it finishes reconfiguring. You can try your new setup. ex. echo “Hi” | mail -s “Testing” email@example.com
19. You should see your email coming into Exchange. By default is comes with the servername as the domain.
21. Now your email will arrive with the correct domain name.