Google no longer supports username and password auth for 3rd party apps.

[sam0jones0]

Source: https://support.google.com/accounts/answer/6010255

Attempting to send email via gmail using email/password combination with "less secure apps" disabled will no longer work.

A workaround is to use an app password in place of your account password (requires 2 factor authentication).

• Update readme re app passwords
• Look into supporting xoauth2