I have checked and triple checked that the settings (SMTP Server, Username, Passsword, etc.) are correct but still no luck.
When I log in to my gmail account I have an email from google...
The workaround is to accept the application or device in your Gmail settings.
Alternatively, you can change your Gmail settings at your own risk.
Another option is to enable an App Password on your Google account, as per the instructions here:
https://support.google.com/accounts/answer/185833/sign-in-with-app-passwords?hl=en&authuser=1
