EML viewer for local email files

What an EML viewer opens

An EML file is a saved email in the form mail systems use to exchange a message: a block of headers followed by one body or a tree of MIME parts. That sounds like ordinary text, but the useful version is not obtained by opening it in a text editor. Sender names may be encoded across several header words, long fields can continue on the next line, a body can be quoted-printable in one alphabet, and a PDF attachment can be base64 inside a nested multipart boundary. This EML viewer reads those relationships from the file bytes and reports what it actually decoded.

The first result separates familiar message fields from structure. From, To, Cc, Bcc, Reply-To, Date, Subject, and Message-ID appear when the file carries them. The Details view explains body alternatives, declared character sets, MIME types, transfer encodings, inline parts, and warnings. Missing values remain missing; the page does not invent an address, date, or subject to make a damaged message look complete.

Plain text, safe HTML text, and raw source are different views

Many messages carry two versions of the same words. The plain body is selected first when it exists. If the file also has HTML, you can choose Safe HTML text, which uses a tokenizer to recover readable words and structural breaks, or Raw HTML source in a read-only field. Neither choice inserts the sender's markup into this page. A message is untrusted input, even when it came from somebody you know, and an email viewer should not turn it into an active website.

That boundary is deliberately visible. Links from the message are not made clickable. Scripts, forms, stylesheets, media URLs, remote fonts, and tracking pixels are not run or requested. A cid: reference points to an inline MIME part; that part is listed with the attachments and can be saved, but is not silently painted into the body. If the job is to extract readable words from HTML you already trust, the HTML to text converter accepts source directly. Here the safer email-specific defaults stay in charge.

Attachments keep their bytes, not dangerous paths

Each attachment row shows the decoded original name, the portable name that a download will use, its media type, and its decoded size. The bytes are not rewritten. Names do need a boundary: path components, control characters, and characters operating systems reserve cannot be allowed to direct a browser outside the downloads folder or smuggle a second header line into a label. They are removed or replaced deterministically, and duplicate names receive (2), (3), and so on before the extension. The original decoded name stays visible so the safety change is never disguised as source data.

A forwarded email attached as message/rfc822 is listed and can be downloaded as another EML. It is not opened recursively in this first version, because nested messages can continue indefinitely and deserve a fresh, inspectable file boundary. Signed payloads are not called verified. Encrypted S/MIME is inventoried and downloadable, but this page does not ask for keys or claim to decrypt it.

EML and MSG are not two names for the same file

EML preserves internet-message headers and MIME parts. Outlook MSG stores a message as a binary CFB container full of numbered MAPI properties. The jobs look alike on screen, but the parsers cannot substitute for one another and changing the extension changes nothing. Use the MSG viewer for a file saved by Outlook with a .msg suffix. Keeping the routes separate also gives a renamed or mismatched file an honest format error instead of a blank message.

Warnings are evidence, not decoration

Old and generated mail is not always tidy. A missing charset can sometimes be handled with a named fallback, and a recoverable defect is reported beside the affected part. A broken multipart boundary, incomplete transfer encoding, or ambiguous structure is different: guessing could attach the wrong words to the wrong header or produce corrupt downloaded bytes. In those cases the viewer stops with a typed explanation and keeps the source selected so you can inspect the problem or try another file.

Very long bodies use a clearly labeled clipped preview so the page remains responsive. Copying uses the complete decoded body or complete raw source, not the visible slice. No arbitrary file-size ceiling is imposed; a large message gets resource advice before work starts and the operation can be canceled.

The message stays local, and this page cannot send mail

The selected file is processed in this tab. Its addresses, subject, body, attachments, and filename are not put into the URL, persisted in browser storage, added to analytics, or sent to a parsing service. The tool has no mailbox login and no reply, forward, or send action. If you need a stable reading copy rather than an inspection surface, the separate EML to PDF converter creates one from the same safe content boundary. The local-processing guide shows how to verify the lack of network transfer yourself.