Use blocklists at the initial point of setting up an email connection. You can reject emails immediately and significantly reduce the amount of processing required during content inspection.

Not all blocklists are reactive. Our pro-active Policy Blocklist helps some customers drop up to 70% of emails at the initial connection, before the HELO stage.

At the initial connection and SMTP transaction don't only use IP blocklists. Domain and Hash blocklists will provide increased protection. Domains can be listed before they're seen in the wild.