To add Guardian Mail to your Exim installation: Single configuration file If you are using a single configuration file, open exim.conf and find the “acl_check_rcpt:” section, and add: deny message = $dnslist_text\ dnslists = <APIKEY>.combined.mail.abusix.zone Replace <APIKEY> with “Your API key” from your account in app.abusix.com. Then restart Exim. Split configuration file If you are using Exim split configuration, then open _/etc/exim4/conf.d/acl/30_exim4-config_check_rcpt and find the“.ifdef CHECK_RCPT_IP_DNSBLS” _ section and add the following after the “.endif”: 
deny
    dnslists = <APIKEY>.combined.mail.abusix.zone
    add_header = X-Warning: $sender_host_address is listed by Abusix ($dnslist_value: $dnslist_text)
    log_message = $sender_host_address is listed by Abusix\n$dnslist_text
Replace <APIKEY> with “Your API key” from your account in app.abusix.com. Then restart Exim.