Standalone Email Verification Tool Development

I'm looking for a professional to develop a standalone email validation tool. The primary function of this tool is to check if an email exists.

Requirements:
- The tool should utilize the best technology available to ensure consistent and accurate results.
- The tool needs to be standalone, not integrated into any existing system.
- It will read emails from an excell/googlesheets file, validate email and provide an output file with conclusion and reasons(s).

Ideal Skills:
- Strong experience in software development, particularly in creating standalone tools.
- In-depth knowledge of the best email verification technologies.
- Ability to deliver a tool with high accuracy and consistency.