Electronic mail, abbreviated as e-mail (or mail), is one of the most important digital communication tools in the business world. E-mails enable the written exchange of messages and documents via the Internet and can be sent around the world in a matter of seconds, almost in real time. Just like regular post, e-mail is a form of asynchronous communication. This means that the sender can send out the message regardless of whether the recipient can receive it immediately or not.
The term “e-mail” refers both to the transmission system and to the individual message that is sent and received.
The first e-mail was sent in October 1971 by Ray Tomlinson, who has been considered the inventor of e-mail ever since.
An e-mail is divided internally into two parts, the header and the body.
The header contains the sender’s address, the recipient’s address, the subject, and the date of creation. It also contains the format of the content and the route taken by the e-mail.
The body, which is separated from the header by a blank line, contains the content of the e-mail, i.e., the information to be transmitted. A signature or attachment is optional and technically part of the body, but is perceived by the user as separate.
In order for an e-mail to be delivered successfully, a unique recipient in the form of an e-mail address is required, such as hello@engity.com. The e-mail address consists of three different parts: the domain part engity.com, the local part hello, and the @ symbol. Translated to the address on a letter, the domain part is the city and the local part is the street and house number where the recipient can be found.
E-mails are sent using software programs and web browsers, also known as e-mail clients. The messages are routed through several servers, which store and forward the messages and finally deliver them to the recipient’s e-mail server. The Simple Mail Transfer Protocol (SMTP) is used for sending, while IMAP or POP3 are responsible for receiving and managing e-mails.
E-mails have become an integral part of the modern business world. Companies use them for internal and external communication, marketing, customer service, and to document business transactions. They are also often used to exchange confidential information, even though e-mails are not inherently a secure system. This makes e-mails an attractive target for attackers.
This allows unencrypted messages to be intercepted, malware to be spread, or individuals to pose as legitimate organizations. Social Engineering, Ransomware, Domain Spoofing, and Spam also threaten e-mail security.
Measures such as encrypting e-mails using Transport Layer Security (TLS) or end-to-end encryption (E2E) contribute to the security and confidentiality of communications. Other techniques include implementing spam filters and firewalls, as well as using authentication mechanisms such as Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and the later introduced Domain-based Message Authentication, Reporting, and Conformance (DMARC).
But no matter what measures are taken today to keep e-mail traffic secure and free of spam, it’s like a game of cat and mouse. The protocol used for sending e-mails is outdated, and none of the measures taken so far have been able to solve the problems fundamentally. This protocol was not designed for today’s world. There are and have been many alternative formats, but they have not really caught on due to the widespread use of traditional e-mail. So, for the time being, we will have to live with this poor alternative.