What's actually inside an .eml file (and how to read one without Outlook)

When you open a .eml file, it's a plain-text file in MIME format. This means it can contain multiple parts, such as text and attachments, separated by a boundary. To read a .eml file without Outlook, you can use a text editor or a parser like the one provided in the article. Be aware of header folding and encoded words when parsing the file.