Email is protected with cyber security through various measures to ensure the confidentiality, integrity, and availability of the information being transmitted. These measures include:

1. Encryption: Encryption is a crucial component of email security. It involves encoding the content of an email in a way that only the intended recipient can decipher. This prevents unauthorized access to the email's contents. One commonly used encryption protocol is Transport Layer Security (TLS), which encrypts the connection between email servers.
2. Authentication: Email authentication verifies the identity of the sender and prevents email spoofing and phishing attacks. Technologies such as Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC) help ensure that emails are sent from legitimate sources and have not been tampered with during transit.
3. Spam Filtering: Spam filters play a vital role in email security. They identify and block unsolicited or malicious emails, reducing the risk of phishing attempts, malware distribution, and other cyber threats. These filters use various techniques like content analysis, blacklisting, and reputation-based filtering to identify and filter out spam emails.
4. Firewalls and Intrusion Detection Systems: Firewalls and intrusion detection systems (IDS) are used to protect email servers from unauthorized access and network attacks. Firewalls monitor and control incoming and outgoing network traffic, while IDS detect and respond to suspicious activity or intrusion attempts.
5. User Education and Awareness: Educating users about email security best practices is essential. Users should be aware of the risks associated with opening suspicious attachments, clicking on unknown links, or sharing sensitive information over email. Regular training and awareness programs can help users identify and avoid common email-based threats.

References:

• Microsoft. (n.d.). Email Security Best Practices. Retrieved from https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/email-security-best-practices?view=o365-worldwide
• Cisco. (n.d.). Email Security. Retrieved from https://www.cisco.com/c/en/us/products/security/email-security/index.html