- Plesk 12.5 for Linux
- Plesk 11.x for Linux
- Plesk 12.0 for Linux
- Domain is sending spam emails with enabled Outgoing Mail Control and disabled "Allow scripts and users to use Sendmail"
- Mails sent from scripts are not presented in the Postfix mail queue
Spam is sent directly to recipients via SMTP protocol or via other mail server acting as open relay.
Disable scripts to send mail to non-local server via SMTP with firewall.Create an
to pass SMTP traffic only from a
The following sample rule will block outgoing SMTP traffic not from
to non-local server IP addresses.
# iptables -I OUTPUT -p tcp --dport 25 -m owner ! --gid-owner mail ! -d <your_server_ip_addresses> -j REJECT
Additional details could be obtained in a iptables manual or in iptables tutorial
Otherwise, to mitigate the risk, you should remove
from whitelist and enforce SMTP authentication.