Error while trying to send telnet email (Windows)

  cmd, email, smtp, telnet, windows

When I’m trying to send email with telnet (no auth) I get an error

550-5.7.1 [<My IP>] The IP you're using to send mail is not authorized to
550-5.7.1 send email directly to our servers. Please use the SMTP relay at your
550-5.7.1 service provider instead. Learn more at
550 5.7.1 g12si23908332wri.283 - gsmtp

I’m using this command in order to send an email

telnet 25

Does anyone know what does that error mean and how do i fix it?

Source: Windows Questions