Frequently asked questions

Office Unbound is an open-source business productivity and communications platform in development. It covers business email and calendars, office documents, file storage with desktop sync, team chat, video meetings and calling, identity and administration. These come together under one sign-in, one interface and one administration layer, so it is not a set of separate applications.

It is built from established open-source projects for the heavy lifting, such as mail servers, office editors, file platforms and messaging servers. Office Unbound’s own work is the layer those projects do not provide: unified identity and interface, central and multi-tenant administration, migration tooling and a branded client experience. See the platform overview and the target architecture.

That is the intent. The long-term goal is to cover the main business functions organizations use Microsoft 365 for: Exchange Online and Outlook, Word, Excel and PowerPoint, OneDrive and SharePoint file storage, Teams, and Entra ID for these services, with administration across all of them.

It is not an equivalent today, and it will not be identical later. Microsoft 365 is a mature platform with a large ecosystem of integrations, compliance tooling and features built over many years. Office Unbound aims to be a credible replacement for everyday business use, on infrastructure the customer chooses. Our Microsoft 365 comparison separates architectural differences from target functionality.

It is designed to replace the major parts of Teams, not just basic chat: direct and group chat, channels, threaded discussion, team workspaces, presence, file sharing, search, guest access, integrated meetings, and retention and auditing for administrators. The leading candidates are the open Matrix standard with Element clients for messaging, and LiveKit or MatrixRTC for real-time media.

Office Unbound does not claim complete Teams parity. The Teams app ecosystem, deep Office integration and some meeting features have no direct equivalent. See team chat and collaboration.

The same goal applies: Gmail, Calendar and Contacts, Drive and Shared Drives, Docs, Sheets and Slides, Meet and Chat, and the admin console, for everyday business use. Two differences matter in practice. Google’s editors use native formats that have to be converted into standard office formats. And Gmail’s labels do not map one-to-one onto folders. Both are covered in the Google Workspace comparison.

Yes, that is a founding principle. The source code for Office Unbound’s own components is intended to be public, so customers, providers and security reviewers can read what they run. The public repository has not been published yet. It will be announced on project updates and to registered developers.

Two caveats. First, the license for Office Unbound’s own code has not been selected. Second, the components it builds on each have their own licenses, some with conditions on branding, network use or commercial editions. The technology and licensing page lists each one.

Yes. That is the main reason it is being built. The platform is designed to run on infrastructure the customer chooses: servers on its own premises, rented or colocated hardware, a private cloud it administers, or infrastructure run by a managed service provider. Running your own means owning the responsibilities as well. Hardware, storage, backups, monitoring, security maintenance and recovery planning become yours or your provider’s. Hosting and deployment options sets out who does what in each model.

Proxmox VE with Linux virtual machines is the initial deployment target. That is the environment the first deployment tooling, documentation and testing will assume. It was chosen because it is open source, widely used by MSPs and smaller hosting providers, and runs separated workloads as ordinary Linux VMs.

The services are standard Linux software, so nothing in the architecture ties them to Proxmox. But other hypervisors or cloud platforms will not be supported or documented until they are tested. If you run something else, tell us through the early-access form. It informs which targets come next.

A branded Office Unbound desktop client for Windows, macOS and Linux is planned for file synchronization. The goals are simple installation, guided setup with automatic account enrollment through single sign-on, background sync, offline access, clear sync status and conflict reporting, and policies administrators can set centrally. The intent is to build on established open-source sync client technology, with the Nextcloud desktop client the leading candidate, subject to licensing and branding review. See files, storage and sync.

For files, yes, with limits. Files the desktop client has synchronized to the computer remain usable when the connection drops, and changes sync back when it returns. Conflicting edits are reported rather than silently overwritten. Files that exist only on the server are not available offline.

Collaborative browser editing, chat and meetings need a connection. Mail depends on the client: a desktop mail client with a local cache keeps working, webmail does not. We are not promising that every cloud workflow works offline.

Not promised. Whether the desktop Outlook application for Windows or macOS works well depends on how completely the selected mail server implements Microsoft’s Exchange protocols (MAPI over HTTP, EWS, ActiveSync). One candidate, grommunio, implements them. Whether the result is good enough for daily use is part of what evaluation must establish, so this is marked Under evaluation.

What is planned regardless: an Outlook-style web client, and standard IMAP, SMTP, CalDAV and CardDAV access for clients such as Thunderbird, Apple Mail and phone mail apps. See business email and calendar.

For everyday documents, the candidate editors (Collabora Online, which is built on LibreOffice, and ONLYOFFICE Docs) open and save .docx, .xlsx and .pptx files directly, and most ordinary business documents round-trip well. Compatibility is not universal. Advanced macros and VBA, some complex layouts, specialized Excel features, embedded objects and proprietary functionality may not behave identically or at all. Organizations with heavily automated spreadsheets or templates should test those specific files. The planned migration assessment is meant to flag them. See documents and office applications.

Yes. Mail on your own domains is the basic design, including several domains per organization and per customer for MSPs. Adding a domain is designed to include the DNS records receiving servers check: MX, SPF, DKIM, DMARC and related records. Moving a domain from Microsoft 365 or Google Workspace means changing those records at cutover. The migration tooling is designed to plan that step rather than leave it to chance.

One identity service sits in front of every workload. A user signs in once and reaches mail, files, documents, chat and meetings without separate passwords. Keycloak is the leading candidate. It speaks OpenID Connect and SAML, supports multifactor authentication, including authenticator apps and security keys, and can connect to an existing LDAP or Active Directory directory. Authentication policies, session controls and audit logs are planned to be set centrally. See identity and administration. This is not Entra ID parity: conditional access, device management and Microsoft-specific integrations are not part of the plan as described.

Tenant isolation is designed in Phase 1, before multi-tenant features are built, because retrofitting it is how cross-tenant leaks happen. The model has separate tenant-specific authorization, strict administrative boundaries so a customer administrator cannot see another customer, data access policies, and resource separation. Where an operator needs stronger separation, it can also run separate service instances or VMs per customer.

Isolation has to be tested as well as designed. Cross-tenant authorization testing is part of the planned security verification, and results will be published as they exist. See security and compliance controls.

The customer or its provider decides when updates are applied. Planned controls include patch notifications, security advisories, maintenance windows, staging before production, update approval and rollback planning, plus an emergency-patch path for critical fixes. An MSP can set update policies across its customers.

Control comes with responsibility. Delaying a critical security patch leaves a known hole open, and the guidance will say so plainly. Updates also cover the underlying components (mail server, file platform, editors), so tracking their advisories is part of the work. See security and transparency.

That is the intent: public source for Office Unbound’s own components, alongside the already-public source of the projects it builds on, plus software bills of materials, release documentation and vulnerability advisories. The repository is not published yet. Readable source makes claims checkable. It does not make software secure by itself, which is why independent review and security testing are on the roadmap too.

Yes. MSP hosting is one of the primary operating models. Planned MSP capabilities include multi-customer provisioning, per-customer delegated administration, technician roles, customer-specific domains and policies, quotas, central monitoring, patch and backup management, migration projects and a provisioning API. No commercial terms or partner program exist yet. See Office Unbound for MSPs or send an MSP partnership inquiry.

That is planned. Office Unbound intends to provide management and provisioning APIs that MSP platforms such as clientst0r can call: creating customers, onboarding and offboarding users, provisioning services, managing mailboxes, groups, storage quotas and domain settings, applying customer policies, and reporting migration status and service health. None of this works today. It belongs to Phase 6 on the roadmap.

MailThreatZero is under evaluation as an optional additional email-security layer for phishing and threat filtering, for organizations that want more than the built-in spam and malware filtering. It would be optional, and as a separate service it may carry its own cost. It is not integrated today.

That is planned: messages, folders, attachments, contacts and calendar events, plus shared mailboxes, aliases and distribution lists, with delegation and calendar permissions where supported. More in the migration FAQ.

That is planned, including history, attachments and sent mail. Labels need a decision about how they become folders, because one message can carry several labels. More in the migration FAQ.

That is planned from both platforms, including recurring events and shared calendars, with sharing permissions where the source exposes them. More in the migration FAQ.

That is planned: files, folder structures, supported metadata and permission mapping, with version history where feasible and handling for large files. More in the migration FAQ.

That is planned for My Drive and Shared Drives, with ownership and sharing mapped where possible. Native Google files are converted on export. More in the migration FAQ.

That is planned for document libraries, site-associated files, folders and supported sharing permissions. Site pages, lists and custom SharePoint apps are not in scope as described. More in the migration FAQ.

Yes, by exporting to standard office formats, with format validation and a compatibility report. Some formulas, formatting, comments or history may not transfer perfectly. More in the migration FAQ.

Only partly, and only where source APIs and permissions allow. Full chat history, meeting recordings and app integrations are not promised. More in the migration FAQ.

They do not transfer. Neither platform exposes passwords or MFA secrets through migration APIs, so users enroll in the new identity service. That step is planned for, not avoided. More in the migration FAQ.

Yes. The design starts with a pilot group, then moves users and workloads in batches. More in the migration FAQ.

That is the intent, with coexistence where feasible. How much works across both systems, such as free/busy lookup or mail routing, depends on the workloads and the cutover plan. More in the migration FAQ.

Failed items are retried and reported, and the source stays untouched and accessible until validation succeeds. A rollback plan cannot undo every externally visible change, such as DNS propagation. More in the migration FAQ.

By comparing counts and content between source and destination per user and per workload, with a report of anything unresolved. More in the migration FAQ.

The software is intended to be open source, which means no per-user license fee for Office Unbound’s own code. That is not the same as free to run. An organization still pays for servers, storage, bandwidth, backups and administrative time, or for an MSP to provide those. Some components have commercial editions or support subscriptions that may be needed at certain scales, and telephony carries carrier charges. No pricing has been set for any commercial offering. We will not claim it is always cheaper than a subscription, because that depends on the organization. See cost and licensing.

Support arrangements have not been defined. Likely routes are community support around the public repository, support from the MSP that hosts a deployment, and possibly commercial support or managed hosting through approved providers later. None exists today, and none is promised in a particular form.

Not yet, and we are not publishing a date. The project is in Phase 1. Components will reach early testing in the order shown on the roadmap. Registering for early access is the way to be contacted when a component you care about is ready to test.

Register on the developer interest form and say where you could help: provisioning and administration services, the web interface, desktop and mobile clients, migration connectors, component integration, security review, documentation or packaging. The public repository, with contribution guidelines and a code of conduct, has not been published yet. Registered developers will be told when it is. See community and contributions.