Microsoft 365 Business vs Stalwart
In short: Microsoft 365 Business wins on privacy, Microsoft 365 Business wins on price, and Microsoft 365 Business wins on features. The full comparison is below, last checked 25 October 2026.
Should you pick Microsoft 365 Business or Stalwart?
- Microsoft 365 Business suits you best if you want your mail kept in the UK data centres for UK tenants (London, Cardiff, Durham) and a company with a longer track record (since 2011).
- Stalwart is the better pick if you want a company that isn't funded by advertising; a free plan to start on; and open-source apps.
| Feature | Microsoft 365 Business | Stalwart |
|---|---|---|
| Overall | 2.5 | Not rated |
| Privacy | 1.0 | Not rated |
| Price | 2.5 | Not rated |
| Features | 5.0 | Not rated |
| Cheapest plan | Business Basic £5.40 per user a month, yearly, ex VAT | Community Free (Enterprise from €2 per mailbox a year) |
| Free plan | No | Yes, open source |
| Storage | 50 GB | Not confirmed |
| Your own domain | ✓ Yes | ✓ Yes |
| End-to-end encryption | No | No |
| Company based in | United States | United Kingdom |
| Your data is kept in | UK data centres for UK tenants (London, Cardiff, Durham) | Your own server |
| Founded | 2011 | 2019 |
| Free trial | One month free on some plans | Free to download |
| Funded by advertising | Yes, or its parent company is | No |
| Works in any mail app | ✓ IMAP and SMTP | ✓ IMAP and SMTP |
| Calendar and contacts | ✓ Yes | ✓ Yes |
| Aliases | Yes | Yes |
| Open-source apps | No | ✓ Yes |
| Sign up without ID | No | No |
| White label | No | Unknown |
| Reader offer | None | None |
| Last checked | 22 October 2026 | 25 October 2026 |
Want to add another? Open this in the compare tool.
The key differences
- On price: Microsoft 365 Business Business Basic at £5.40 per user a month, yearly, ex VAT, against Stalwart Community at Free (Enterprise from €2 per mailbox a year).
- For free, Microsoft 365 Business gives you no free plan, and Stalwart a free plan (open source).
- Microsoft 365 Business comes with 50 GB of storage and Stalwart with storage not confirmed.
- Microsoft 365 Business keeps your mail in the UK data centres for UK tenants (London, Cardiff, Durham), while Stalwart keeps it in Your own server.
- Microsoft 365 Business is based in the United States and Stalwart in the United Kingdom, so different privacy laws apply.
- Only Microsoft 365 Business is part of an advertising business.
Questions people ask
Do Microsoft 365 Business and Stalwart work with my own domain?
Yes, both do. Microsoft 365 Business: Yes. Stalwart: Yes.
Where do Microsoft 365 Business and Stalwart keep my email?
Microsoft 365 Business keeps it in the UK data centres for UK tenants (London, Cardiff, Durham). Stalwart keeps it in Your own server.
Recent price changes
- 27 July 2026 Microsoft 365 Business: £5.40 (UK price change from 1 July 2026)
- 1 June 2026 Microsoft 365 Business: £4.90
The latest headlines: Microsoft 365 Business news · Stalwart news.
Also worth a look
- mailbox.org4.5 out of 5 overall
- Proton Mail for Business4.0 out of 5 overall
- Tuta Business4.0 out of 5 overall
Microsoft 365 Business vs mailbox.org · Stalwart vs mailbox.org · Microsoft 365 Business vs Proton Mail for Business · Stalwart vs Proton Mail for Business · Microsoft 365 Business vs Tuta Business · Stalwart vs Tuta Business
Moving your email
Moving to Microsoft 365 Business · Moving from Microsoft 365 Business. Or see all my switching guides.