Are you trying to set up for a project, or just looking for a marketing tool ?
That post title looks like a classic "get-rich-quick" scheme for spammers, which usually leads to a few not-so-great outcomes:
Using "unlimited free" SMTPs usually results in your emails going straight to spam or getting your IP banned instantly.
If you're looking for ways to send emails reliably, it’s much safer to use the of legitimate services like SendGrid , Mailgun , or Amazon SES . They give you a solid amount of monthly sends for free without the security risks.
The "method" might just be a trick to steal your own email credentials.
Those .txt files or download links often hide scripts that can infect your computer.