22 Sept 2025•7 min read
Understanding Email Under the Hood: A Developer's Guide
Like many developers, I’ve used email libraries to send messages, created MimeMessage objects, and attached files. But until recently, I didn’t really know what was happening under the hood. If you’ve ever asked yourself questions like “What actually happens when I press send?”, “Why do I have to add all these DNS entries?”, or “How does SPF or DMARC actually stop spoofing?”, this post is for you. From Plain Text to MIME Originally, email was just plain ASCII text. No attachments, no emojis,