Tune spam filtering:
Enable DNSBL checks:
docker compose exec rspamd-mailcow bash
# Edit /etc/rspamd/local.d/dnsbl.conf
dnsbl {
enabled = true;
rules {
SPAMHAUS zen.spamhaus.org {
returncodes = ["127.0.0.2-255"];
symbol = "SPAMHAUS";
}
}
}
Enable greylisting:
Limit outbound mail to reduce abuse from compromised accounts:
# docker-compose.override.yml
services:
postfix-mailcow:
environment:
- RATELIMIT_SENDER=100/hour
- RATELIMIT_DOMAIN=500/hour