Proton Mail vs Fastmail
Proton Mail encrypts mailboxes so that Proton itself cannot read them, under Swiss law, and accepts weaker search, a Bridge application for desktop clients and slower exports as the price. Fastmail is plain standards-based mail from Australia with instant search and an import tool that simply works. One is bought for a threat model, the other for convenience.
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Choose Proton Mail ifthe provider being unable to read your mail is the requirement, Swiss jurisdiction matters to you, and staff can live with the Bridge application and search that runs on the device.
Choose Fastmail ifyou want fast mail, calendar and contacts on open protocols, a painless import from your old account, unlimited aliases and domains within a plan, and Australian jurisdiction is acceptable.
Proton Mail and Fastmail side by side
| Proton Mail | Fastmail | |
|---|---|---|
| Our business email hosting rank | #8 of 18 | #1 of 18 |
| Established in | Switzerland | Australia |
| Pricing | Per user per month, published | Per user per month, published |
| Free tier | — | — |
| Open source | — | — |
| Self-hostable | — | — |
| Built for | Firms handling sensitive material where the provider must not read it | Teams that want mail, calendar and contacts done properly and nothing more |
| Not for | Companies needing journaling, archiving or eDiscovery tooling for compliance | Organisations needing documents and video meetings in one contract |
Both are reviewed in full in our business email hosting ranking: Proton Mail and Fastmail.
Where they differ
Proton Mail 1 · Fastmail 2 · open 1- 01
What the provider can read
Proton encrypts mailbox contents at rest so that the company cannot read them, which is an engineering commitment and the reason to buy it. Fastmail is conventional standards-based hosting over IMAP and JMAP, and our data makes no equivalent claim for it. For firms handling sensitive material where the host must not see it, Proton is the one built for that.
Depends on the buyer
- 02
Which country's law applies
Proton is established in Switzerland, which keeps it outside the CLOUD Act. Fastmail is Australian, and Australian law allows agencies to compel technical assistance, which weakens the case for choosing it on privacy grounds. If keeping a particular government's reach away from your mail was the reason for moving, Proton's position is the stronger of the two.
Edge: Proton Mail
- 03
Moving years of existing mail
Fastmail's import tool connects to the old account directly, resumes where it stopped and lets people keep working while the archive comes across. Proton is a hard case: encrypted storage means the import runs through its own client on somebody's laptop, and getting a large archive out again later is slow and awkward. Fastmail makes the migration far less of a project.
Edge: Fastmail
- 04
Search, desktop clients and system mail
Fastmail searches instantly across years of archive and speaks IMAP and JMAP natively. With Proton, search happens on the device and is weaker over a long archive, desktop clients need the Bridge application to use IMAP, and automated senders such as an accounting system need separate SMTP credentials. Day to day, Fastmail asks less of users and administrators.
Edge: Fastmail
When neither fits
Both are mail specialists, and Fastmail deliberately has no document editing. If documents must sit in the same subscription as the mailboxes, Google Workspace attaches them to mail everyone already knows, and mailbox.org adds an Open-Xchange document layer to German-hosted mail at a lower price per mailbox.
Proton Mail or Fastmail: questions
3 answersIs Proton Mail more private than Fastmail?
On the two points our data covers, yes. Proton encrypts mailboxes so that it cannot read them and is established in Switzerland, outside the CLOUD Act.
Fastmail is Australian, where agencies can compel technical assistance, so moving to it is a change of country and not an escape from that kind of reach.
Which is easier to migrate to, Proton Mail or Fastmail?
Fastmail. Its import tool pulls an existing account across directly and resumes if interrupted. Proton's encrypted storage means imports run through its own client on a laptop, which is slower for a large archive, and bulk export afterwards is slow as well.
Can I use Outlook or another desktop client with Proton Mail and Fastmail?
Fastmail supports IMAP and JMAP directly, so standard clients connect without extra software. Proton Mail requires its Bridge application on the desktop to speak IMAP, and systems that send mail automatically need separate SMTP credentials, so test those before committing.