Microsoft 365 Business vs Fastmail for Business
On privacy it's Fastmail for Business. On price it's Fastmail for Business. On features it's a tie. Here's everything side by side, last checked 22 October 2026.
Microsoft 365 Business or Fastmail for Business: which should you choose?
- Fastmail for Business suits you best if you want a company that isn't funded by advertising; to pay less: $5 per user a month ($4.17 yearly); and features the other lacks, like catch-all address as well as sieve filters.
| Feature | Microsoft 365 Business | Fastmail for Business |
|---|---|---|
| Overall | 2.5 | 3.0 |
| Privacy | 1.0 | 2.0 |
| Price | 2.5 | 3.5 |
| Features | 5.0 | 5.0 |
| Cheapest plan | Business Basic £5.40 per user a month, yearly, ex VAT | Standard $5 per user a month ($4.17 yearly) |
| Free plan | No | No |
| Storage | 50 GB | 50 GB |
| Your own domain | ✓ Yes | ✓ Up to 100 |
| End-to-end encryption | No | No |
| Company based in | United States | Australia |
| Your data is kept in | UK data centres for UK tenants (London, Cardiff, Durham) | EU (Amsterdam) for UK customers, with a US replica and US backups |
| Founded | 2011 | 1999 |
| Free trial | One month free on some plans | 30 days free |
| 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 | No |
| Sign up without ID | No | No |
| White label | No | No |
| Reader offer | None | Offer 10% off your first year, plus a free trial of up to 30 days |
| Last checked | 22 October 2026 | 22 October 2026 |
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Where they differ
- Microsoft 365 Business's cheapest plan is Business Basic (£5.40 per user a month, yearly, ex VAT); Fastmail for Business's is Standard ($5 per user a month ($4.17 yearly)).
- Microsoft 365 Business keeps your mail in the UK data centres for UK tenants (London, Cardiff, Durham), while Fastmail for Business keeps it in the EU (Amsterdam) for UK customers, with a US replica and US backups.
- Microsoft 365 Business is based in the United States and Fastmail for Business in Australia, so different privacy laws apply.
- Only Microsoft 365 Business is part of an advertising business.
Questions people ask
Which is more private, Microsoft 365 Business or Fastmail for Business?
Fastmail for Business scores 2 out of 5 for privacy and Microsoft 365 Business 1. Fastmail for Business gives you a company that isn't funded by advertising.
Which is cheaper, Microsoft 365 Business or Fastmail for Business?
Fastmail for Business is cheaper. Its Standard plan is $5 per user a month ($4.17 yearly), against £5.40 per user a month, yearly, ex VAT for Microsoft 365 Business's Business Basic. Check the renewal price before you pay, as some first-year prices go up.
Do Microsoft 365 Business and Fastmail for Business work with my own domain?
Yes, both do. Microsoft 365 Business: Yes. Fastmail for Business: Up to 100.
Where do Microsoft 365 Business and Fastmail for Business keep my email?
Microsoft 365 Business keeps it in the UK data centres for UK tenants (London, Cardiff, Durham). Fastmail for Business keeps it in the EU (Amsterdam) for UK customers, with a US replica and US backups.
Price changes and news
- 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 · Fastmail for Business news.
Alternatives to Microsoft 365 Business and Fastmail for Business
Microsoft 365 Business vs mailbox.org · Fastmail for Business vs mailbox.org · Microsoft 365 Business vs Posteo · Fastmail for Business vs Posteo · Microsoft 365 Business vs Proton Mail · Fastmail for Business vs Proton Mail
Moving your email
Moving to Microsoft 365 Business · Moving from Microsoft 365 Business. Or see all my switching guides.