The creator describes this as their first open-source project, and notes that the success rate depends entirely on the quality of the dictionary. This type of tool is far more controversial than email verification. Today, attempting such authentication against major providers without explicit permission is a violation of their terms of service and potentially illegal in many jurisdictions. Always ensure any script you use is compliant with all applicable laws and the terms of service of the services it interacts with.
To extend this base script into an enterprise utility, consider implementing these expansion features:
If this is for educational purposes about email security (with explicit permission to test), please specify the legitimate context.