Siftbox is an email prioritization service that helps people identify important messages without changing their existing inbox. Compatible with Gmail, Outlook and supported IMAP mailboxes, it organizes new emails into four categories: Urgent, Important, To Read and To Ignore. Each classification includes a brief explanation, and users can correct it with one click; Siftbox uses those preferences to improve future sorting.

Designed for personal, professional and shared inboxes, Siftbox places its categories or folders directly in the mail service or client people already use. It does not delete or send emails, draft replies, or turn messages into helpdesk tickets. Users remain in control and can disconnect their mailbox at any time. The service is hosted in Europe and uses a Mistral model hosted by Infomaniak in Switzerland for classification; the company says relevant data is used only for this purpose and not to train models or for advertising. Siftbox is offered free during its beta, with no credit card required.