: A modern, open-source MTA designed specifically to replace PowerMTA. It is built for high-volume sending (millions of messages per hour) and uses a Lua policy engine for flexibility.

PowerMTA 6.0r2 released | Overview of features - Postmastery

The term "nulled" refers to a pirated or cracked version of software, often distributed through online forums, torrent sites, or other unofficial channels. PowerMTA nulled versions claim to offer a free or cracked version of the software, often with promises of unlimited sending capacity, no restrictions, and no need for licensing or authentication. These versions are typically created by individuals or groups who have reverse-engineered the software, bypassing its licensing and security features.