EML.io is a lightweight Windows desktop viewer and converter for .EML and .MSG email files. Open messages without importing them into a mailbox, read HTML or plain-text content, inspect attachments and embedded messages, and move quickly between email files. Save or export messages as EML, HTML or PDF. Attachments can be opened, saved individually, saved in bulk, or dragged out of the app. EML.io can also hand a message to the default mail application and print it directly. For larger archives, Batch Conversion processes multiple EML/MSG files to PDF or HTML, with configurable attachment handling and file-renaming options based on date and subject. Light/dark themes, English/Italian interface, zoom, keyboard shortcuts and a built-in tutorial make the app practical for everyday email-file review and archiving.