What Is an Email Firewall?

E-mail security refers to the fact that e-mails are obtained or tampered with by attackers, virus mails, spam mails, mail bombs, etc., which seriously endanger the normal use of e-mails and even cause serious damage to computers and networks.

With the rapid development of computer technology and the widespread popularity of the Internet, e-mail is increasingly used in all aspects of social production, life, and learning, playing a pivotal role. While people enjoy the convenience and speed of e-mail, they must also have e-mail security issues brought about by the openness of the Internet and computer software vulnerabilities, such as: attackers obtaining or tampering with mail, virus mail, spam, Mail bombs and other serious threats to the normal use of e-mail, and even cause serious damage to computers and networks.

Email security encrypts email

Since there is no way to organize the attacker to intercept the data packets transmitted on the network, the only measure that can be taken is to encrypt the data before sending the email, and decrypt the data after the receiver receives the email. Processing, this way, even if the attacker intercepts the e-mail, he is just a bunch of garbled meaningless. The so-called encryption refers to the conversion of a plaintext message into an insignificant ciphertext through the conversion of an encryption key and an encryption function. When necessary, the ciphertext is restored to the plaintext through a decryption function and a decryption key. The most commonly used encryption software is PGP (Pretty Good Privacy). PGP is an email encryption software based on the RSA (Rivest Shamir Adleman) public key encryption system. It proposes public key or asymmetric file encryption and digital signature. The RSA algorithm is a public key system based on the assumption of impossible prime factorization of large numbers. Simply put, it is to find two large prime numbers, one of which is open to the world and calls it the "public key", and the other does not tell anyone and calls it the "private key". The two keys are complementarythe ciphertext encrypted with the public key can be decrypted with the private key, and vice versa. Suppose A sends a letter to B. They know the other party's public key. A can use B's public key to encrypt the mail and send it. After B receives it, use A's private key to extract the original text of A. This will ensure the security of the mail. Prevent unauthorized people from reading, and digitally sign messages to convince recipients that the message was sent by you.

Email security using firewall technology

A firewall is a network communication security monitoring system established between a protected internal network and an external network. It can also be called a threshold for controlling communication in and out of both directions. The corresponding network communication monitoring system is established at the network boundary to isolate the internal and external networks to prevent the intrusion of external networks. Currently, there are three types of firewalls: packet filtering firewall, proxy firewall, and dual-hole host firewall. Among them, the most widely used firewall is a proxy firewall, also known as an application-level gateway-level firewall, which is composed of a proxy server and a filtering router. The filtering router is responsible for network interconnection, strictly selects the data, and then transmits the filtered data to the proxy server. The proxy server acts as an intermediate relay for external network applications to access the internal network. Its function is similar to a data repeater. It mainly controls which users can access which service types. When the external network applies for a certain network service to the internal network, the proxy server accepts the application, and then it decides whether to accept the service according to its service type, service content, serviced object, service application time, and domain name range of the applicant. Service, if accepted, it forwards the request to the internal network, thereby protecting the internal network from unauthorized access.

Email security updates virus database in a timely manner

Computer viruses are constantly generating and evolving variants. Anti-virus software manufacturers will always add new virus code to the virus database according to the newly discovered virus situation, so users must upgrade their anti-virus software in a timely manner.

Email Security Identifying Mail Viruses

Some mail viruses have a wide range of common characteristics. Finding out what they have in common can prevent damage from viruses. When receiving an email, first look at the size of the message and the address of the other party. If you find that the message contains no content and no attachments, the size of the message itself is tens of K or more, or the suffix of the attachment is double suffix, Most likely it contains a virus, you can delete this message and empty the trash. After emptying the waste bin, be sure to compress the mailbox again, otherwise the antivirus software will report a virus when it next checks for viruses.

Email security opens real-time monitoring firewall

Real-time monitoring technology builds a dynamic, real-time anti-virus defense line for e-mail and system security. It modifies the operating system to make the operating system itself with anti-virus functions and reject viruses outside the door of computer systems. And because the excellent anti-virus software uses the underlying seamless connection technology with the operating system, the system resources occupied by the real-time monitor are extremely small, and the user can hardly feel the impact on the performance of the machine, and need not consider the problem of virus intrusion. ^[1]