Base64 in Emails: MIME Encoding Explained
Email attachments and HTML bodies use Base64 MIME encoding. Learn how Content-Transfer-Encoding works and how to decode email payloads manually.
Published:
Tags: encoding, email, base64
Base64 in Emails: How MIME Encodes Attachments and HTML Bodies Email was designed in the 1970s for ASCII text. When people started attaching files and sending HTML, the protocol needed a way to carry binary data over a system built for 7-bit text. The answer was Base64 — and it's been baked into every email ever since. Understanding how email clients encode content with Base64 lets you debug delivery issues, write MIME messages from scratch, and decode attachments manually when you need to. The MIME Standard MIME (Multipurpose Internet Mail Extensions) is defined in RFC 2045–2049. It extends the email format to support: Non-ASCII characters in headers and bodies Multi-part messages (attachments alongside text) Binary file attachments The central mechanism for carrying binary data is the…
All articles · theproductguy.in