touch /etc/blockeddomains
echo “domain.com” >> /etc/blockeddomains
WHM > Exim Configuration Editor > Advanced Editor

domainlist blocked_domains = lsearch;/etc/blockeddomains

#route
democheck:
driver = redirect
require_files = “+/etc/demouids”
condition = “${if eq {${lookup {$originator_uid} lsearch {/etc/demouids} {$value}}}{}{false}{true}}”
allow_fail
data = :fail: demo accounts are not permitted to relay email

reject_domains:

driver = redirect
# RBL Blacklist incoming hosts
domains = blocked_domains
allow_fail
data = :fail: Connection rejected: SPAM source $domain is manually blacklisted.