EML File Viewer

Parses raw RFC 5322 / MIME mail (the .eml exports your client makes) without sending a byte to a server. It unfolds wrapped headers, splits multipart bodies on the declared boundary, decodes Quoted-Printable and Base64 transfer encodings, and lists attachments with their original filenames, MIME types and encoded sizes. Switch between plain-text and HTML parts when a message has both, and toggle raw mode to see exactly what's on the wire.

A MIME message is a tree rather than a document, and the viewer shows it as one. multipart/alternative holds the same content twice and the client is supposed to display the last part it understands, which is why the HTML version is usually what you saw in your mail app even though the plain-text one is listed first. multipart/mixed holds genuinely different parts, and multipart/related holds a body plus the images it references by Content-ID. A message can nest all three.

Attachment sizes are reported as encoded, which is what the file actually contains. Base64 inflates by roughly a third, so a 4 MB attachment occupies about 5.3 MB of the message, and a mailbox quota counts the larger figure. A filename is also just a header value: it can carry a different extension from the part's declared MIME type, and the two disagreeing is worth noticing rather than resolving.

What the parse cannot tell you is whether any of it is true. Every header, From included, is text the sender wrote, and the only parts with a cryptographic basis are a DKIM signature or the verdicts your own inbound server added. Reading a suspicious message here is safe because nothing is executed or fetched, but the content is still a claim.

Everything runs locally on the file you open, which is the point when the message is one you would not upload to a third-party parser.