Currently, Plesk only allows enabling DNS Blackhole Lists (DNSBL), which automatically rejects messages on SMTP level if the sending IP is listed.
It would be very useful to have an option in the Plesk interface to choose between:

Reject mode – block connections immediately (current behavior)

Warn mode – only log or tag DNSBL hits but still pass them to SpamAssassin/Amavis for scoring

This would give administrators finer control and prevent legitimate senders from being rejected while still benefiting from DNSBL scoring.