Features
Everything you need in a desktop email client. Nothing you don't.
Email Management
A classic three-pane layout that puts you in control. Manage multiple accounts from a single window, organize your folders, and handle messages with the speed and precision you expect from a desktop client.
- Three-pane layout with resizable panels
- Multi-account support — Gmail, Outlook, Yahoo, Fastmail, self-hosted, and more
- Full folder management — create, rename, move, and delete
- Message operations — move, copy, archive, delete, mark read/unread, flag
- Multi-select messages with shift-click and ctrl-click
- Drag-and-drop messages between folders and accounts
Compose and Reply
Write emails the way you want. A full rich text editor, separate compose windows, inline replies, and all the tools you need to communicate clearly and efficiently.
- Rich text editor with formatting toolbar
- Separate compose window for focused writing
- Inline reply, reply-all, and forward
- Drag-and-drop file attachments
- Auto-save drafts so you never lose work
- Contact autocomplete from your address book
- Per-account email signatures
Email Rendering
HTML emails look the way they should. Box uses Shadow DOM isolation and smart processing to display even the most complex newsletters and marketing emails beautifully — including in dark mode.
- Smart padding that adapts to email content
- Dark mode rendering with intelligent color inversion
- Shadow DOM isolation prevents email styles from leaking
- CID embedded image support for inline attachments
- Sanitized HTML to strip scripts and dangerous content
Search
Find any email instantly. Box uses SQLite FTS5 full-text search to index your messages locally, so search results are fast, private, and available offline.
- SQLite FTS5 full-text search engine
- Search across subject, sender, recipients, and body
- Filter results by account, folder, and date range
- Dedicated search window for deep exploration
Security and Authentication
Your credentials are safe. Box uses OAuth2 where available, stores passwords in your OS keyring, and enforces encrypted connections. You can even inspect email authentication headers with visual badges.
- OAuth2 authentication for Gmail, Outlook, and supported providers
- IMAP and SMTP connections secured with TLS/SSL
- Credentials stored in your OS keyring — never in plaintext
- Email header viewer with SPF, DKIM, and DMARC authentication badges
Desktop Integration
Box is a native desktop application, not a web wrapper. It respects your system theme, sends real notifications, supports keyboard shortcuts, and works with your desktop environment the way a local app should.
- System theme detection — follows your light or dark preference
- Desktop notifications for new mail
- Keyboard shortcuts for common actions
- Print emails directly from the app
- .eml file support — open and save standard email files
- Export and import account configurations
Offline and Reliability
Box works even when your network doesn't. An offline-first architecture backed by SQLite means your email is always accessible. Outgoing messages queue automatically and send when connectivity returns.
- Offline-first SQLite database — read and search without a connection
- Outbox for queued outgoing messages
- Deferred sync queue that retries automatically
- Dual IMAP connection strategy for reliable syncing
- Virtualized message lists for smooth performance with large mailboxes
Additional Features
- Download all attachments from an email with one click
- Inline audio playback for audio attachments
- Auto-discover server configuration from email address
- 35+ built-in provider presets for quick account setup
- Window state persistence — remembers size, position, and layout
Ready to try Box?
Download Box for free and experience email the way it should be.