Penguin Mail is a desktop email and calendar application for Linux and macOS, made by Pivotd. It brings Gmail, Microsoft, and other IMAP or POP3 accounts together in one app, with options to view all accounts in a unified inbox or separately. The app also supports contacts and calendars from Google, Microsoft, and compatible CardDAV or CalDAV providers. Users can organize messages with Gmail categories, rules, flags, VIPs, and customizable Smart Mailboxes, as well as schedule messages, undo sending, and perform actions on multiple emails at once.

Additional features include OpenPGP and S/MIME signing and encryption through the user’s own GnuPG, Markdown composition, reusable templates, and Hide My Email addresses for Gmail. An optional assistant can summarize messages, draft replies, answer questions about mail, and help manage calendars; it can use local models or supported external services. Penguin Mail is free software licensed under GPL-3.0-or-later. The company says it has no server of its own, tracking, or ads, and that supported accounts connect directly to their providers.