Examine the email headers to find out which MTA is the last hop before it hits your network. All large companies use content delivery networks that may have IP blocks overlapping country assignments, especially since the IPv4 space is getting fuller.If you can, configure a separate route for your inbound email to by-pass Suricata or configure a whitelist.Bart...
You could run a dual-homed MTA on a DMZ with a LAN interface and only run intrusion detection on the OPNsense LAN interface.Bart...