Cannot authenticate with Gmail

Question: I downloaded your MaxBulk Mailer to test it out. Functionality seems good and I would be happy to buy a license, however for the world of it, I cannot connect it to my email SMTP server. I inputted my correct Gmail address and password and only get error messages, trying out different options like TLS and SSL.

I also got a security alert from Google saying that a 'less secure app' is trying to connect. So I enabled permissions that 'less secure apps' are allowed to connect, but nevertheless I could not authenticate your software with Gmail. Please help. Thanks.

Answer: The Gmail settings are explained here: