vi /etc/localdomains
domaina.com
domainb.com
vi /etc/exim/exim.conf
domainlist sender_domains = lsearch;/etc/localdomains
acl_check_rcpt:
accept hosts = +relay_from_hosts
sender_domains = +sender_domains
control = submission
control = dkim_disable_verify
accept hosts = +relay_from_hosts
sender_domains = +sender_domains
control = submission
control = dkim_disable_verify
require message = bad sender domain
domains = +sender_domains
tail -f /var/log/exim/main.log
2020-05-20 20:55:55 H=mail.server.com [xx.xx.xx.xx] F=<> rejected RCPT
2020-05-20 20:55:55 H=mail.server.com [xx.xx.xx.xx] F=<> rejected RCPT