Tag: design-network

All the articles with the tag "design-network".

• System Design - How Email Delivery Works: SMTP, DNS, SPF, DKIM, and DMARC

  31 Oct, 2026

  A practical guide to Internet email delivery: how SMTP servers discover recipients with DNS, how message transfer differs from mailbox access, and how SPF, DKIM, and DMARC reduce spoofing.