Sep 13, 2018

How to fix python Gmail smtplib.SMTPAuthenticationError 534, 5.7.14

Google blocks sign-in attempts from apps which do not use modern security standards (mentioned on their support page). You can however, turn on/off this safety feature by going to the link below:
Go to this link and select Turn On
https://www.google.com/settings/security/lesssecureapps
A login/password is not a modern mechanism to authenticate. You should implement SASL XOAuth2.