Email

Both parse with the pure-Rust mail-parser crate. peek also recognises a message by content, so an extension-less file still opens here when it starts with a From separator (mbox) or an RFC822 header block.

.eml — a single message

Cycled with Tab:

• Message (default) — a header block (From / To / Cc / Date / Subject, plus an attachment count when the message has attachments) followed by the body. HTML messages render through the same html2text driver as the HTML viewer; plain-text messages are word-wrapped to the terminal width.
• Source — the raw RFC822 text. --plain skips the rendered view and opens straight on the source.
• Attachments (only when the message has any) — one row per MIME attachment with its content type and size. Press e to extract the selected attachment to disk; Enter opens it with a recursive peek.
• Info — the header summary (see below).

As with every file, x opens the hex dump and h / ? the help screen.

The default Message view: the header summary followed by the rendered body.

.mbox — a mailbox

The default view is a Messages list, one row per message (prefixed with its position so duplicate subjects stay distinct, with the message date alongside). Press Enter to drill into a message — it opens with the same views as a standalone .eml (Message, Attachments, Info, hex, help), minus the per-message raw Source view: the mailbox's own raw text is the secondary top-level view instead. The mailbox is read as a stream and only the opened message is parsed, so even a very large mailbox lists instantly.

Info

The Info view shows the header summary plus the attachment count and total size (.eml), or the message count (.mbox).