==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.2 MARIADB edition
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version: AlmaLinux 8
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I have one server which would need to get its emails out to the Internet via my iRedMail server. So restricting the relay function to only allowing that IP would be preferable. I've looked at the instructions from https://docs.iredmail.org/relayhost.html but not sure how to proceed...