EML Viewer Online — open .eml files without Outlook

MSG is the file format Microsoft Outlook uses to save a single email, contact, or calendar item. It stores the header (sender, recipient, subject, timestamp), the message body, and any original attachments in one file — which is why it can typically only be opened natively in Outlook.

An .eml file is plain text — a mail client's export of a single message in RFC 5322 / MIME form. Windows and macOS that live without Outlook have nothing built in to render it, so a double-click shows a raw text dump or the webmail error. This viewer parses the message structure in the page itself and lays it out like a mail client: a header block with sender, recipients and date, a body you can switch between formatted and plain text, and every attachment listed with its size and a save button. Because parsing is local, viewing an .eml never uploads it — and the same parse result feeds every converter on this site if you want a copy.