Fix: email-service-revamp

Description

This PR introduces a complete revamp of the email service within the application. The overhaul focuses on improving the reliability, performance, and scalability of the email-sending functionality. Key updates include the integration of a new email delivery provider, enhanced email template management, and the introduction of robust error handling and retry mechanisms.

Summary of Changes:

Integrated [New Provider Name] as the new email delivery service for improved email handling.
Shifted email processing to an asynchronous model to improve application performance.
Improved logging and monitoring for better tracking and diagnostics of email-related issues.

Key Changes:

New Email Delivery Provider Integration: Switched from the existing email service provider to [hng.email]
Enhanced Email Templates: Implemented a new templating system that allows for more flexible and dynamic email content generation. Templates can now be easily managed and updated without requiring code changes.
Asynchronous Email Processing: Emails are now processed asynchronously to avoid blocking main application workflows, improving overall system performance.
Logging & Monitoring: Added comprehensive logging and monitoring for email delivery, enabling better tracking of email status and quick identification of issues.

Related Issue (Link to Github issue)

No related issue link provided.

How Has This Been Tested?

The revamped email service was tested across multiple scenarios to ensure reliability and performance. This included sending emails under various conditions (e.g., network issues, high load), testing the retry logic, and verifying the accuracy of email templates.

Tests Performed:

Unit Tests: Created new unit tests to validate the logic of the email-sending process and the new error handling mechanisms.
Integration Tests: Verified the integration between the application and the new email delivery provider to ensure smooth operation.
Load Testing: Conducted load testing to evaluate the performance and scalability of the new asynchronous email processing system.
Manual Testing: Manually tested the entire email flow in a dev environment to ensure all changes work as expected.

Screenshots (if appropriate - Postman, etc):

Types of changes

[ ] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[X] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

[x] My code follows the code style of this project.
[x] I have updated the documentation accordingly.
[x] I have added tests to cover my changes.
[x] All new and existing tests passed.

hngprojects / hng_boilerplate_golang_web