EMails

Emails, short for electronic mail, are messages exchanged over a network. A typical message includes headers (From, To, Subject, Date) and a body that may be plain text or formatted content, and often attachments. The MIME standard allows multimedia content within a single message. Email uses a client–server model: users compose messages in an email client, and servers handle storage, routing, and delivery.

Core protocols include SMTP for sending messages and POP3 or IMAP for retrieval. SMTP transfers messages between mail servers, while POP3/IMAP provide mailbox access to clients. Addresses use the RFC 5322 format, and DNS MX records guide routing.

Email originated on ARPANET in the 1960s and 1970s. Ray Tomlinson implemented the first networked email system in 1971 and popularized the @ address. Standards were formalized later in RFCs such as 5322 (Internet Message Format) and 5321 (SMTP).

Security and privacy: Messages can be intercepted in transit; TLS encrypts server connections, and end-to-end encryption is available via S/MIME or OpenPGP. Authentication mechanisms like DKIM, SPF, and DMARC help combat spoofing and spam. Email remains a common vector for phishing and malware.

Impact and usage: Email is a ubiquitous tool in personal, educational, and business contexts. It enables asynchronous communication and record-keeping but faces challenges from spam, privacy concerns, and data retention. It remains supported by a wide range of clients and services.