Looks like you are using a corporate account and most probably you have two factor authentication enabled. In these cases you have to generate a App Password from Gmail & use it for sending emails instead of the login password. More Details here : Sign in with App Passwords - Gmail Help
I hope you are using the correct Username (As is) & Password (The App Password you just generated). Can you please post the properties you are using ? Like STMP Server, Port .etc (the ones that don’t contain any sensitive info).