Osiris compared: features, prices and the real 5-year cost
As mailbox count grows, Osiris's one-time licence usually ends up cheaper over 5 years than a per-seat backup subscription, and you keep your own storage and an open, restorable format the whole way.
A fact-by-fact comparison against Veeam Backup for Microsoft 365, Veeam Data Cloud, NinjaOne SaaS Backup (formerly Dropsuite), MailStore, Acronis, Keepit, AvePoint, Datto SaaS Protection and Microsoft 365 Backup, for IT decision makers and MSPs evaluating options: what each product actually is, what it costs over time with real infrastructure counted in, and what Osiris honestly does not cover yet.
Compiled from each vendor's own public documentation and pricing pages, checked 2026-09-24. Not a recommendation against any of these products; several are good software with a different model than Osiris. Prices and features change: every claim below is dated and sourced.
Feature matrix
"Yes" and "No" mean the vendor's own official documentation states so; "Not documented" is a negative finding (not found in the sources checked), not proof of absence. Osiris is marked honestly: SharePoint and Teams are not in v1, the GoBD-compliant archive layer is still in development, and infrastructure/Proxmox backup is planned for a later track. Every vendor name links to that vendor's own dedicated, fully sourced comparison page.
| Feature | Osiris Community | Osiris Business | Osiris Service Provider | Veeam Backup for Microsoft 365 | Veeam Data Cloud for M365 | NinjaOne SaaS Backup (Dropsuite) | MailStore Server / SPE | Acronis Cyber Protect Cloud | Keepit | AvePoint Cloud Backup | Datto SaaS Protection | Microsoft 365 Backup |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Self-hosted | YesSelf-hosted, Docker Compose | YesSelf-hosted, Docker Compose | YesSelf-hosted, Docker Compose | YesSelf-hosted, Windows server | NoSaaS, Veeam-operated on Azure | NoSaaS, vendor-operated on AWS | YesSelf-hosted (Server/SPE); Cloud is SaaS | NoSaaS | NoSaaS, vendor-hosted only | NoSaaS | NoSaaS, MSP channel | NoSaaS, Microsoft-operated |
| Your own storage target | YesLocal disk, S3-compatible, NFS/SMB | YesLocal disk, S3-compatible, NFS/SMB | YesLocal disk, S3-compatible, NFS/SMB | YesLocal (DAS/SMB), S3-compatible, Azure Blob | NoVeeam-operated Azure storage accounts | NoVendor-operated AWS storage | YesFile system or NAS (Server/SPE) | PartialAcronis cloud storage, or Microsoft 365 Backup Storage | NoVendor-operated storage | NoVendor-operated storage | NoVendor-operated storage | NoMicrosoft-operated storage |
| Data location control | YesYou choose the storage target's region | YesYou choose the storage target's region | YesYou choose the storage target's region | YesYou choose the storage target's region | PartialSelectable Azure region, incl. Germany West Central | PartialSelectable AWS region, incl. Germany | YesYour own file system/NAS (Server/SPE) | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | PartialFollows the M365 tenant's own region |
| Open storage format / restore without the vendor | YesDocumented format, standalone osiris-restore tool | YesDocumented format, standalone osiris-restore tool | YesDocumented format, standalone osiris-restore tool | NoNo open format specification found | NoNo open format specification found | NoNo open format specification found | PartialEML/MSG/PST export; internal store format not openly specified | NoNo open format specification found | NoNo open format specification found | NoNo open format specification found | NoNo open format specification found | NoNo open format specification found |
| IMAP backup | Yes | Yes | Yes | NoNot documented for VBM365 | No | YesIMAP/POP3 supported | YesIMAP/POP3, plus M365/Exchange/Google | NoNot documented | NoNot documented | NoNot documented | NoNot documented | NoM365-native only |
| M365 mail, calendar, contacts, OneDrive | Yes | Yes | Yes | Yes | Yes | Yes | PartialMail-focused archive; calendar/contacts depend on profile | Yes | Yes | Yes | Yes | Yes |
| SharePoint / Teams | PlannedNot in v1, see roadmap | PlannedNot in v1, see roadmap | PlannedNot in v1, see roadmap | YesSharePoint and Teams (excl. 1:1/group chats) | Yes | YesIncl. Teams channel chat | NoNot documented | Yes | Yes | Yes | Yes | PartialSharePoint yes; Teams coverage per Microsoft's own docs |
| Immutable storage (Object Lock / WORM) | PartialWhere the storage target supports it (e.g. S3 Object Lock) | PartialWhere the storage target supports it (e.g. S3 Object Lock) | PartialWhere the storage target supports it (e.g. S3 Object Lock) | YesS3 Object Lock, Azure versioning, depending on target | YesIncluded, LRS with 3 copies | PartialWORM advertised for the archive product | NoHash-based tamper detection; no WORM storage documented | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked |
| Automated restore tests | YesWeekly sampled restore check, compared byte for byte; results shown as recovery readiness | YesWeekly sampled restore check, compared byte for byte; results shown as recovery readiness | YesWeekly sampled restore check, compared byte for byte; results shown as recovery readiness | NoNot documented as of the 8.6 release notes checked | Not documentedNot researched | NoNot documented | NoIntegrity check exists; automated test-restore not documented | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked | Not documentedNot documented in vendor sources checked |
| Multi-tenant for MSPs | NoSingle tenant | NoSingle tenant | YesDelegated tenant admins, cross-tenant reporting and API | YesVia VCSP program | YesVia VCSP program | YesMSP-oriented, white label for qualifying resellers | YesMailStore SPE, one instance per end customer | YesMSP-channel product | Not documentedNot researched | Not documentedNot researched | YesMSP-channel product (Kaseya) | NoPer-tenant, no MSP console documented |
| Pricing model | YesFree, no licence key | YesOne-time purchase; all updates included while Osiris is actively developed | YesOne-time purchase; all updates included while Osiris is actively developed | PartialSubscription or monthly rental per protected user | PartialSubscription per user (annual/multi-year/monthly) | PartialPer user/seat subscription | PartialPerpetual per-user licence + separate time-limited update subscription | PartialPer-seat or per-GB subscription | PartialSubscription, tiered by retention/support level | PartialSubscription, per user or per data volume | PartialCommitted-minimum-plus-consumption subscription | PartialPay-as-you-go, $0.15/GB/month |
| Open source | YesAGPL-3.0 | PartialAGPL-3.0 core, proprietary Enterprise modules | PartialAGPL-3.0 core, proprietary Enterprise modules | No | No | No | No | No | No | No | No | No |
Pricing and the real 5-year cost
Self-hosting is never free: every Osiris total below includes a Hetzner Cloud VM, Hetzner Object Storage sized for the protected data (with a stated deduplication factor), and an explicit, separately labelled admin-time cost. Where a vendor publishes an exact price (Microsoft 365 Backup's $0.15/GB/month), it is used directly; where none of the compared vendors publish one, a clearly labelled illustrative per-seat figure is shown instead, never attributed to a specific vendor. See assumptions and sources below for every number used.
Read honestly: at a very small, low-data scale (the 25-mailbox scenario below), Microsoft's own metered $0.15/GB/month can come out cheaper than self-hosting, because Osiris's fixed VM and admin-time costs don't shrink with mailbox count. Osiris pulls ahead of both Microsoft 365 Backup and a typical per-seat subscription as mailbox count and data volume grow, which is exactly what the mid-size and MSP scenarios show.
Show values as a table
| Model | 5-year total |
|---|---|
| Microsoft 365 Backup | €1,975 |
| Osiris (self-hosted) | €5,769 |
| Per-seat SaaS (illustrative) | €6,585 |
Show values as a table
| Model | 5-year total |
|---|---|
| Osiris (self-hosted) | €10,775 |
| Microsoft 365 Backup | €11,853 |
| Per-seat SaaS (illustrative) | €39,510 |
Show values as a table
| Model | 5-year total |
|---|---|
| Osiris (self-hosted) | €34,063 |
| Microsoft 365 Backup | €79,020 |
| Per-seat SaaS (illustrative) | €263,400 |
Not charted: Veeam Backup for Microsoft 365 (self-hosted). Its licence is sold per protected user through resellers and no public list price exists, so a bar with only its server, Windows and storage costs would understate the real total. Other vendors without a published price are covered by the illustrative per-seat figure.
Run your own numbers
The three scenarios above use round numbers. If your mailbox count, data volume or time horizon is different, use the calculator below; it runs entirely in your browser from the same data as the chart.
Run your own numbers
Adjust the mailbox count, protected GB per mailbox and the time period; the totals below recompute instantly, using the same assumptions as the chart above.
- Osiris, self-hosted, total
- -
- Microsoft 365 Backup, total
- -
- Illustrative SaaS subscription, total
- -
Assumed VM size: -
Why MSPs choose Osiris
- A one-time licence instead of per-seat margin erosion. Service Provider is €950 once; a per-user subscription keeps taking a cut of every mailbox you protect, every month, for as long as you protect it.
- Multi-tenant with delegated admins from day one. Tenant administrators, cross-tenant reporting, and a scoped provider API key, not a shared login per customer.
- Your own storage and data location. Local disk, S3-compatible object storage, or NFS/SMB, in the region you choose, not a vendor-operated bucket you can't inspect.
- An RMM/PSA REST API. Backup, restore and verify status, jobs, storage and archive evidence, and a clean per-tenant mailbox directory for your ticketing and billing systems.
- Your customer's data in an open, documented format. A standalone restore tool reads it even without a running Osiris server; no vendor lock-in on exit.
- No per-mailbox reporting to a vendor. What you protect and for whom stays between you and your customer.
- Restore proof per tenant. A backup without a verified restore is treated as failed and shown as such, not quietly assumed to be fine.
- White label, planned. Not built yet, see the roadmap for status.
Example: margin on the 20-tenant / 1,000-mailbox scenario
This is a worked example with a stated example price, not a promise of what you will charge or earn. Using the same infrastructure and admin-time assumptions as the chart above, the MSP's own all-in monthly cost for 1,000 mailboxes across 20 tenants averages to about €0.57 per mailbox per month (licence amortized over 5 years, plus VM, storage and admin time). Charging customers an example €3/mailbox/month for managed backup:
- Example monthly revenue
- €3,000
- MSP's own all-in monthly cost
- €568
- Example monthly margin
- €2,432
€3/mailbox/month is an example price point only, not a recommendation or a guarantee of what the market will bear; your actual price, cost and margin depend on your own infrastructure choices, support load and market.
Assumptions and sources
Every figure in the chart and calculator above is either read from an official vendor source (with a date) or marked as an explicit, replaceable assumption. Prices and features change; this page shows the state as of the date given, not a standing guarantee.
- Exchange rate: 1 USD = 0.878 EUR, as of 2026-09-24(source: Federal Reserve H.10, a snapshot, not a live rate).
- Microsoft 365 Backup: $0.15/GB/month, official list price, read 2026-09-24 (source: learn.microsoft.com, "Pricing model for Microsoft 365 Backup").
- Osiris licence prices: Community free; Business €250 net, one-time; Service Provider €950 net, one-time, all updates included for as long as Osiris is actively developed, no support included(source: /en/pricing/).
- Hetzner Cloud VM prices: CX23 (2 vCPU, 4 GB RAM) €5.49/month, CX33 (4 vCPU, 8 GB RAM) €8.49/month, CX53 (16 vCPU, 32 GB RAM) €29.49/month, net prices, read 2026-09-24 (source: docs.hetzner.com, price adjustment effective 15 June 2026, cross-checked against Hetzner's own pricing API).
- Hetzner Object Storage: €6.49/month base fee (includes roughly 0.93 TB), additional storage €6.26/TB/month, read 2026-09-24 (source: website-price-api.hetzner.com and docs.hetzner.com/storage/object-storage).
- Windows Server 2025 Standard (16-core pack): €939 estimated, unverified: not independently re-verified against Microsoft's current price list in this research pass.
- Deduplication factor: 1.5x, a stated assumption, not a measurement from a production install.
- Assumed protected data: 10 GB/mailbox (assumption).
- Admin time: €80/hour (stated hourly-rate assumption), 1/2/6 hours/month across the three scenarios (small/mid/MSP), an assumption.
- Illustrative per-seat SaaS backup: $5/user/month, reused from the already-sourced pricing-math page, explicitly not attributed to any named vendor(see that page).
- Own hardware instead of a cloud VM: not costed in the chart above. A mini-PC or a used tower server in the price range of one of the VMs above (roughly €300 to €1,500 one-time, highly build-dependent) plus electricity can replace the recurring VM rental; the object-storage and admin-time line items are typically unaffected.
This page is comparative advertising under UWG Section 6: objective, verifiable and dated, without disparagement. Where no public price was found for a competitor, that is stated explicitly rather than estimated. The individual vendor pages under /en/compare/ carry each vendor's own detailed sourcing.
Vendor by vendor
- Veeam Backup for Microsoft 365
- Veeam Data Cloud for M365
- NinjaOne SaaS Backup (Dropsuite)
- MailStore Server / SPE
- Acronis Cyber Protect Cloud
- Keepit
- AvePoint Cloud Backup
- Datto SaaS Protection
- Microsoft 365 Backup
Each page above cites its own sources with the date read. See also Your data is your data and the topics section for the reasoning and lock-in questions behind these comparisons.
Frequently asked
Is self-hosting Osiris really cheaper than a subscription?
Usually, over 5 years, once you count the real infrastructure and admin-time cost, which this page does rather than pretending self-hosting is free. It is not a law of nature: a very small, rarely-changing mailbox count and a generous per-seat discount can close the gap. The three worked scenarios below show the actual arithmetic with every assumption stated, so you can substitute your own numbers.
What does Osiris cost for an MSP with 20 tenants?
The Service Provider edition is €950 once, net, with all updates included for as long as Osiris is actively developed. For the worked 20-tenant / 1,000-mailbox scenario on this page, adding realistic infrastructure (a Hetzner Cloud VM, Object Storage sized for the protected data, and a stated admin-time assumption) brings the 5-year total to the figure shown in the chart below, still a one-time licence rather than a per-seat meter that keeps growing.
Why don't the competitor bars use Veeam's or MailStore's actual subscription price?
Because none of them publish one. Veeam Backup for Microsoft 365 is sold per protected user as a subscription or monthly rental with no public list price; MailStore's perpetual per-user licence and update-subscription pricing is quoted per deal. Where a vendor publishes an exact figure (Microsoft 365 Backup's $0.15/GB/month), this page uses it. Where none exists, either the vendor is left out of the chart or a clearly labelled, non-vendor-specific illustrative figure is used instead, exactly as the sourced pricing-math page already does. See each vendor's own comparison page for what is and isn't documented.
Does Osiris cover SharePoint and Teams?
Not in v1. This is a deliberate scope decision, not an oversight, so v1 can focus fully on Exchange mail/calendar/contacts, OneDrive and IMAP. SharePoint, Teams and infrastructure backup are planned as a dedicated track after v1; see the roadmap for status.
Is the GoBD-compliant archive layer available today?
No, it is in development. Osiris is built for GoBD-compliant use (journal receipt, hash-chained WORM storage, enforced retention, legal hold, auditor export) but is not GoBD-certified, and no vendor's archive product carries an official positive certification from the German tax authorities, since none is issued for software. See the roadmap for the archive layer's current status.
What's the catch with a one-time licence and 'unlimited' updates?
No catch: all updates are included in the purchase price for as long as Osiris is actively developed, with no separate update fee. If development ever stops, twelve months' notice is given and the Business/Service Provider modules are published under the AGPL, so the version you bought keeps running indefinitely with no forced shutdown and no phone-home licence check. Licences include the software and all updates; no support is included. There is no renewal fee, which is exactly why the 5-year total on this page is just the one-time licence price plus infrastructure and admin time.