Fix .NET Website Backend Issue with Excel Export on Secured Server

My .NET website has a backend issue that needs urgent fixing. The Excel export feature, which was working previously, has suddenly stopped triggering. There are no specific error codes or descriptions.

Your main tasks will include:
- Diagnosing the Excel export issue
- Implementing a solution to restore functionality
- Ensuring the fix is compatible with our secured server
- Email Notification function not working

Ideal skills and experience for the job include:
- Proven expertise in .NET
- Prior experience with backend web development
- Familiarity with Excel export functionality
- Knowledge of configuring for secured servers
- Ability to diagnose and fix generic error messages

I need someone who can resolve this issue swiftly and effectively to minimize disruption to our services.
Include word "lilypad" at starting of your bid.