Osiris documentation
Osiris backs up Microsoft 365 mailboxes (mail, calendar, contacts) and OneDrive, and IMAP mailboxes, to storage you choose and control, and restores them non-destructively by default — alongside what is already there, not over it. It is open source (AGPL-3.0) and self-hosted. Osiris is currently in closed beta; there is no public release date yet, and archiving is in development, not shipping.
Pick where to start:
- “I use Osiris to find and restore my own mail and files.” Start at For end users → Get started.
- “I run Osiris.” You install, configure or operate it for an organization — start at For administrators → Get started.
- You want the concept, not the click-path — Backup vs. archive and GoBD and evidence explain what each part of Osiris is actually for.
- You want to know what exists today — Status and roadmap.
About this documentation
Section titled “About this documentation”This site has two audiences, kept in separate sidebar sections because they need different things from Osiris: end users, who sign in to look after their own mailbox, and administrators, who install, configure and operate Osiris for an organization or, in the Service Provider edition, for several tenants. Search (top of the page) runs entirely in your browser against an index built at deploy time — no query leaves your device.