Inspect an exported email with explicit MIME limits

Read one exported message, not an entire mailbox

An EML file stores an individual email message with headers and a MIME body. This viewer is useful when someone sends an exported message and you want to inspect its subject, sender, recipients, date and readable body without importing it into your regular inbox. It does not sign in to a mail provider, synchronize folders or verify that the displayed sender actually sent the message. A forged From header can look ordinary. Treat an unfamiliar message as untrusted even when it opens successfully. Keep the original file separate from any text or HTML copy you export for reference.

Choose a supported message

Select a nonempty file ending in .eml, within 20 MiB. The file needs recognizable message headers followed by a blank line separating the body. UTF-8 and ASCII body charsets are supported. A single plain-text message or a flat multipart message is the practical input model. Nested multipart messages and other declared body charsets are rejected with a message rather than presented as a complete interpretation. If a message from an archive will not open, use the mail application that created it to export a simpler UTF-8 copy. Renaming an Outlook MSG file does not convert its internal format into EML.

Worked example: a small dispatch note

Create a test message with From set to dispatch@example.com, To set to receiving@example.com and Subject set to Crate 42 arrival. After a blank line, write Please reserve shelf B7. Save this fictional example as dispatch.eml using UTF-8 text. Opening it should show Crate 42 arrival as the subject, the two addresses in the properties card and the shelf instruction in the plain-text tab. A Date header is optional; a missing date is shown as missing rather than invented from the computer clock. The example contains no attachment, so an empty attachment section is the expected result.

Check encoded text and attachment bytes separately

Common encoded subject headers are decoded for display, and Base64 or quoted-printable text bodies can be read. These encodings describe how bytes travel inside a message; they do not prove authenticity or confidentiality. Detected attachments must use Base64 transfer encoding for this viewer. Download an attachment only when you know what it is, then inspect it using an appropriate application. The viewer does not execute the attachment, scan it for malware or guarantee that its filename matches its actual contents. Messages using another attachment transfer encoding should be opened in a complete mail client instead of relying on this simplified parser.

HTML preview has deliberate restrictions

An HTML email may contain formatting that differs from its plain-text alternative. Inspect both when available. The preview sanitizes the markup and places it in a restricted frame; active content and external resources are restricted. Some newsletters therefore lose images, interactive controls or decorative styling. This behavior does not mean that the original sender omitted them. Conversely, a visually plausible preview does not establish that a link is trustworthy. Avoid using a message's own branding or display name as identity evidence. Contact the supposed sender through a separately known route when an instruction involves passwords, payments or account changes.

Export a reading copy and keep its context

The text export includes the displayed message details and body as readable text. HTML export creates a sanitized reading document with the message subject and common properties. Neither export is a replacement for the original EML when you need the original headers, MIME structure, signatures or forensic evidence. Print opens a separate browser window and requests the browser print dialog; a blocked popup can prevent that window from opening. Inspect the print preview before saving to PDF. Pagination, fonts and background printing depend on the browser, and the viewer does not create a searchable archive or certify a legal record.

Handle missing or unexpected content

A parse error, an unsupported nested message or an unfamiliar charset is a reason to switch applications, not to assume that the message is empty. Some emails supply only HTML, while others supply only plain text. A plain-text placeholder can therefore coexist with a readable HTML alternative. If an expected attachment is absent, compare the original MIME structure in a full mail client. The parser is intentionally limited and cannot promise complete handling of every mail export. Clear the current message before opening a different one, and confirm the new subject and recipients before exporting or sharing a reading copy.

Processing, memory and disclosure

The selected file is read in browser memory, and parsing and attachment decoding occur locally. This tool has no mailbox login or email-processing endpoint. The surrounding website still makes ordinary page, analytics or advertising requests as described in its privacy information. Downloads create additional copies on your device; a text or HTML export can expose the same personal details as the original message. Close the page when finished on a shared machine, remove unneeded downloads and follow your organization's retention rules. Local processing is useful for limiting transfers, but it does not make an already compromised device safe or grant permission to inspect somebody else's correspondence.

A short acceptance checklist

For a message you own, compare the subject, sender, recipients and body against the originating mail application. Include a small known attachment and compare its downloaded bytes with the original file. Try a plain message and an HTML alternative separately. Confirm that a clearly invalid text file produces an error and does not leave the previous message visible. These checks establish whether this viewer suits your particular export. They do not demonstrate universal MIME compatibility. For signed mail, encrypted mail, nested conversations, calendar invitations or rich archive workflows, retain a full email application as the authoritative reader.

EML Viewer — Open EML Files Online