Email: SMTP, IMAP and POP3
How email travels from sender to inbox: SMTP for sending and relaying, MX records, IMAP and POP3 for reading, the ports and TLS, SPF, DKIM and DMARC for authentication and deliverability, sending email from applications through providers, testing locally with Mailpit, and why your messages land in spam.
CodexBash, , 6 min read
Email is one of the oldest internet services still in daily use, and nearly every application sends it: sign-up confirmations, password resets, receipts and notifications. Behind a simple "Send" button sit several protocols and DNS records that decide whether a message arrives, and whether it lands in the inbox or the spam folder. This article explains the journey of an email, the protocols that carry and retrieve it, the authentication standards that fight spoofing, and practical advice for sending email from your own applications.
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