Fastmail vs Microsoft 365 Business
In short: Fastmail wins on privacy, Fastmail wins on price, and they tie on features. The full comparison is below, last checked 22 October 2026.
Which should you choose?
- Fastmail is the better pick if you want a company that isn't funded by advertising; the lower price ($5 a month, yearly); and extras such as catch-all address as well as sieve filters.
| Feature | Fastmail | Microsoft 365 Business |
|---|---|---|
| Overall | 3.0 | 2.5 |
| Privacy | 2.0 | 1.0 |
| Price | 3.5 | 2.5 |
| Features | 5.0 | 5.0 |
| Cheapest plan | Individual $5 a month, yearly | Business Basic £5.40 per user a month, yearly, ex VAT |
| Free plan | No | No |
| Storage | 50 GB | 50 GB |
| Your own domain | ✓ Yes | ✓ Yes |
| End-to-end encryption | No | No |
| Company based in | Australia | United States |
| Your data is kept in | EU (Amsterdam) for UK customers, with a US replica and US backups | UK data centres for UK tenants (London, Cardiff, Durham) |
| Founded | 1999 | 2011 |
| Free trial | 30 days free | One month free on some plans |
| Funded by advertising | No | Yes, or its parent company is |
| Works in any mail app | ✓ IMAP and SMTP | ✓ IMAP and SMTP |
| Calendar and contacts | ✓ Yes | ✓ Yes |
| Aliases | Masked email and aliases | Yes |
| Open-source apps | No | No |
| Sign up without ID | No | No |
| White label | No | No |
| Reader offer | Offer 10% off your first year, plus a free trial of up to 30 days | None |
| Last checked | 22 October 2026 | 22 October 2026 |
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How Fastmail and Microsoft 365 Business differ
- Cheapest plans: Fastmail Individual, $5 a month, yearly. Microsoft 365 Business Business Basic, £5.40 per user a month, yearly, ex VAT.
- Your mail is stored in the EU (Amsterdam) for UK customers, with a US replica and US backups with Fastmail, and in the UK data centres for UK tenants (London, Cardiff, Durham) with Microsoft 365 Business.
- The companies sit under different laws: Fastmail in Australia, Microsoft 365 Business in United States.
- Microsoft 365 Business (or its parent company) makes money from advertising; Fastmail doesn't.
- Aliases: Fastmail offers masked email and aliases, Microsoft 365 Business yes.
Fastmail and Microsoft 365 Business: your questions
Is Fastmail more private than Microsoft 365 Business?
Fastmail scores 2 out of 5 for privacy and Microsoft 365 Business 1. Fastmail gives you a company that isn't funded by advertising.
Is Fastmail cheaper than Microsoft 365 Business?
Fastmail is cheaper. Its Individual plan is $5 a month, 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.
Can I use my own domain with Fastmail or Microsoft 365 Business?
Yes, both do. Fastmail: Yes. Microsoft 365 Business: Yes.
Where is my email stored with Fastmail and Microsoft 365 Business?
Fastmail keeps it in the EU (Amsterdam) for UK customers, with a US replica and US backups. Microsoft 365 Business keeps it in the UK data centres for UK tenants (London, Cardiff, Durham).
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: Fastmail news · Microsoft 365 Business news.
Alternatives to Fastmail and Microsoft 365 Business
Fastmail vs mailbox.org · Microsoft 365 Business vs mailbox.org · Fastmail vs Posteo · Microsoft 365 Business vs Posteo · Fastmail vs Proton Mail · Microsoft 365 Business vs Proton Mail
How to switch
Ready to move? My step-by-step guides cover your mail, contacts, forwarding and your own domain: Fastmail to Microsoft 365 Business · Microsoft 365 Business to Fastmail.