Email is considered one of the most popular communication media in personal, professional, and business communication in the modern digitalized world. Nevertheless, traditional email systems can be easily hacked, data leaks and, in the nearest future, quantum computer attacks that can break the existing encryption techniques quite easily. In order to counter these threats, it is suggested to implement a Post-Quantum Secure Email System that will provide communication privacy and security to users on a 100 percent basis. The system is similar to Gmail, except that it offers a much higher degree of security, all emails are encrypted prior to leaving the sender and can only be decrypted by the intended recipient, using the Kyber (ML-KEM) algorithm to transmit secret keys, the Dilithium (ML-DSA) algorithm to verify the identity of the sender and integrity of the message and the XChaCha20- Poly1305 algorithm to encrypt the email itself at high speed and with high security. Because the server does not store the actual messages but encrypted ones, the message cannot be read or manipulated by the administrators. This protocol offers an effective compromise between protection and performance, and the system can stay quantum-resistant, privacy-conscious, and have cryptographic integrity verification. The suggested system is a solid initiative towards developing a next-generation secure email communication, which will be safe even during the quantum computing age.

• Post-Quantum Cryptography
• Secure Email System
• Kyber (ML-KEM)
• Dilithium (ML-DSA)
• XChaCha20-Poly1305
• Quantum-Safe Communication
• End-to-End Encryption
• Data Privacy
• Digital Signature
• Zero-Knowledge Security

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