What's Causing This Error
It is a generic error that can occur for various reasons mentioned below.
- Invalid SMTP configurations.
- Invalid username/password.
- Invalid use of SSL or TLS.
- Configuration issues with Python.
Solution - Here's How To Resolve It
Given that the error is a generic Python SMTP error, there is no proper solution. However, you may try the solutions mentioned below to try and resolve the error.
- Ensure that you're trying to connect to the correct SMTP host on the correct SSL or TLS port (as per the host's guidelines).
- Verify that you've provided the correct username/password.
- In rare cases, if you've not installed Python correctly, the mail classes may not get initialized correctly. I've personally encountered this error and found that re-installing Python to the latest version fixes the error.