- Plesk for Linux
- Domain is sending spam emails with enabled Outgoing Mail Control option and disabled Allow scripts and users to use Sendmail option.
- 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 that acts as open relay.
Modifying firewall rules:
- Connect to the server via SSH
Forbid scripts to send mail to non-local server via SMTP with the firewall. For example, creating the following
# iptables -I OUTPUT -p tcp --dport 25 -m owner ! --gid-owner mail ! -d <server_ip_addresses> -j REJECT
Modifying Mail White List:
Go to Tools & Settings > Mail Server Settings > White List and remove