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Intro. Create a Python program that enables users to send SMS messages through SMTP to multiple recipients simultaneously. The program should have a user-friendly interface and efficient performance. Implement error handling and validation mechanisms to ensure reliability. Use clear labels and instructions for a seamless user experience. The program should be in English and utilize a tab layout with icons on the left side for easy navigation. Allow users to add multiple SMTP servers, with a clear indication of success (mail icon) or failure (mail icon with a cross) when adding new servers. Enhance user experience with a visual progress bar that has a red and black color scheme to provide real-time feedback on the sending of emails. Implement a system that dynamically determines the optimal number of threads based on the system specifications, taking into account CPU usage and available RAM, to optimize performance.

Mass SMTP-to-SMS Sender with Dynamic Thread Optimization

@John Fortnite