Config: set up email sending using sendgrid

[happy-devs]

Summary

This PR introduces the email service using Sengrid and comprehensive logging functionality to better track and debug email sending operations.

New Features

• comprehensive logging system with different log levels (INFO, DEBUG, ERROR)
• validation of SendGrid environment variables during initialization
• detailed step-by-step logging for email sending process
• Added status code logging for both success and failure cases
• Added logging configuration in main application

Bug Fixes

• Fixed environment variable validation by adding explicit checks
• Improved error handling with detailed error messages and stack traces
• Enhanced debugging capability for unauthorized access issues

Checklist

• I have read the contribution guidelines.
• My code follows the style guidelines of this project.
• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• I have added required dependencies to requirements.txt
• I have updated the documentation (if applicable).

Additional Notes

The logging system now creates both console output and a log file (app.log) with the following features:

• Timestamp for each log entry
• Module name where the log was generated
• Log level (INFO, DEBUG, ERROR)
• Detailed message with context

This will help track down email delivery issues, particularly the 401 Unauthorized errors, by providing more context about:

• Environment variable loading
• API key validation
• Email preparation steps
• SendGrid API responses

To test these changes:

1. Ensure SENDGRID_API_KEY and SENDGRID_FROM_EMAIL are properly set in .env
2. Check app.log for detailed logging output
3. Monitor console output for real-time logging information