Fastmail has been selling email since 1999, and the company that runs it — Fastmail Pty Ltd, Melbourne, ABN 31 142 646 580 — is still independent and employee-owned, which in this category is rarer than any cryptographic feature. It is also the provider in this category that will tell you, in its own documentation, that it does not build end-to-end encryption into its apps and does not intend to. Everything else about the product follows from that decision: a mature, fast, feature-dense mail service with server-side search, spam scanning and previews, whose privacy case rests on where the company is registered, who owns it, and what it publishes about the requests it receives. If you want cryptography to be the thing standing between you and your provider, this is the wrong product, and Fastmail says so before you do.

Security

Start with the omission, because it is a stated position rather than a gap. Fastmail does not offer end-to-end encryption in its webmail, desktop or mobile apps, and its own security FAQ argues against adding it. The reasoning is worth following because it is technically coherent. E2EE requires both sender and receiver to support it through a key-exchange infrastructure that, in Fastmail’s assessment, does not exist at scale today. Adding it to webmail buys little against a compromised server anyway, since the decryption code itself is delivered by that server — if you cannot trust the server to serve honest code, you cannot trust it to serve honest encryption code. And forcing it costs real functionality: no fast server-side full-text search, no efficient message previews, no content-level spam analysis, and a lost private key meaning permanently unreadable mail history. Fastmail’s conclusion is blunter than most vendors would print. If you trust the server, E2EE adds nothing over encryption at rest and in transit; if you do not, third-party PGP or S/MIME is the honest answer, and if what you actually need is end-to-end encrypted messaging, its FAQ points you at Signal rather than at email.

The practical consequence is the key model. Fastmail holds the encryption keys — its Data Protection Agreement states that all encryption keys are retained solely under Fastmail’s control — and server-side processing of unencrypted content is what powers search, calendar alarms, spam filtering and previews. This is not zero-access storage and is not presented as such. There is no automatic encryption between two Fastmail users either. PGP and S/MIME work through third-party clients with manual key management; nothing in Fastmail’s own interface handles keys for you.

Below that line, the engineering is careful. Data in transit uses TLS 1.3 with Perfect Forward Secrecy, in place on supporting browser connections since July 2012. Strict Transport Security is set on every page, closing off SSL-stripping attacks. A Content Security Policy restricts webmail to Fastmail’s own scripts, and untrusted content — attachments, user-hosted sites — is isolated on separate domains (fastmailusercontent.com, user.fm) so it can never reach fastmail.com’s origin or cookies. Two-factor authentication covers U2F hardware keys, and passkeys are supported for passwordless, phishing-resistant login. Account passwords are stored non-reversibly; the handful of credentials Fastmail must be able to reverse on your behalf, such as stored POP logins, are encrypted with keys held separately inside hardware security modules.

Physical handling is documented to the same level. Fastmail owns and operates its own servers rather than renting capacity from a hyperscaler, and data is encrypted at rest on disk at every location including backups, inside locked racks in facilities with video surveillance, backup power, fire suppression and 24x7 monitoring. Data-center “remote hands” staff have no logins, no keys and no data access — physical maintenance only. Internally, staff work against obfuscated data by default; viewing actual customer content requires escalation with justification, and every such access is logged and audited. Fastmail states that across 25-plus years it has never had to sanction an employee for a privacy violation, though the policy allowing termination and prosecution exists. Logs are kept 180 days. Deleted mail and calendar items remain restorable for 7 to 14 days. Closed-account data is purged somewhere between 37 days and a year depending on history and whether closure was voluntary.

Two verification signals need to be kept apart, because they are not equivalent. The first is weak: the DPA claims Fastmail “undergoes external audits by vendors, including penetration tests against our systems to ensure that we meet or exceed industry standards,” with no named firm, no date, and no report published anywhere. That is a described practice, not evidence, and it should not be read as a named, dated, public audit. The second is genuinely strong: a bug bounty program running since at least 2014 with a continuously updated public Hall of Fame naming the researcher, the vulnerability class and the payout, against a stated range of $100 to $5,000. The 2026 entries alone include $3,750 for missing calendar ACL checks and Cyrus memory mismanagement, and $2,000 for an Android app credentials flaw. Twelve years of publicly itemized findings is real evidence that outsiders are testing the system and being paid when they break it. It is still not an audit, and Fastmail should not get credit for one.

One incident belongs here for completeness and needs accurate framing. In October 2021, Fastmail and several other independent email providers were targeted by a coordinated DDoS extortion campaign from an actor calling itself “Cursed Patriarch,” demanding 0.06 BTC by Tor-routed email and threatening escalation. Peak traffic exceeded 270 Gb/sec against a normal baseline under 10 Gb/sec. Fastmail did not pay, mitigated through in-application rate limiting, data-center traffic shaping and an external scrubbing service engaged only as needed, and worked with law enforcement. Its statement afterwards was that no mail was lost and user data remained safe. This was an availability event, not a data breach — nothing was accessed or exfiltrated — and the relevant read is that the service absorbed a 27x traffic spike from an extortionist without paying.

Privacy & Trust

Australian jurisdiction is the structural argument, and it is a more specific one than “not the United States.” Under Australian Privacy Principle 6, Fastmail is legally forbidden from disclosing information directly to foreign authorities; a request from abroad has to come through Australian law-enforcement channels to be actionable at all. A US-Australia CLOUD Act agreement signed in 2021 did not change that until the process actually came into force in January 2024, which is when Fastmail received its first requests under it. Every request is checked for legal validity before anything happens, and invalid ones — wrong jurisdiction, malformed, demands from individuals, direct approaches from foreign agencies — are refused or contested. Fastmail states it provides no dragnet access and responds only to warrants for specific users.

The transparency report backs this with itemized yearly figures rather than a total. In 2025, 16 valid requests, 5 actioned: 2 through mutual law-enforcement treaty, 10 from the Australian Federal Police, 4 from state police, resolving to 2 subscriber-information disclosures and 3 of stored communications. 2024: 16 received, 13 actioned, 11 of them via treaty. 2023: 16 received, 12 actioned. 2022: 11 received, 9 actioned. 2021: 33 received, only 16 actioned. The breakdowns matter as much as the counts — separating subscriber information from stored message content tells you what was actually handed over, and the gap between requests received and requests actioned shows validity checking doing something rather than existing on paper.

Data residency became a user choice in August 2026. Until then everything lived in the US; now an account’s primary region can be the EU (Amsterdam) or the USA (Philadelphia or St Louis), on hardware Fastmail owns and runs at every site. The limits are stated with unusual directness, and they are substantial. EU accounts get their primary copy in Amsterdam, but the geographically separate replica still sits in a US location because only one EU site exists so far. Emergency encrypted backups for every account, regardless of region, are stored in Philadelphia. System logs are consolidated in the US. Some metadata — email addresses, user and customer metadata, Files storage, linked third-party service details — replicates to every site globally. Fastmail’s own wording: “If what you need is a guarantee that your data remains only in the EU, we don’t have that, and we’d rather tell you directly than let you assume otherwise.” And regardless of which region you pick, an Australian company answers Australian legal process identically. Choosing the EU region changes where the primary copy sits; it does not change whose law applies.

The ownership structure is the other durable signal. Fastmail is independent and employee-owned — not venture-backed, not absorbed into a conglomerate whose incentives could change with the next funding round or acquisition. It also runs a US entity, Fastmail US LLC, from a Philadelphia satellite office, and operates the Topicbox and Pobox brands alongside the main service. The company partners with Electronic Frontiers Australia, Digital Rights Watch, the Australian Privacy Foundation and Communications Alliance.

On data handling, the commitments are narrow and checkable. No profiling for personalized content or ads — automated processing exists only for fraud, spam and security detection. No sale of personal data. No training of AI models on customer data, added explicitly to the privacy policy’s update log, with any optional AI feature routed through Anthropic’s API with model training switched off. IP logs are kept up to a year for fraud monitoring, and a closed account’s email address is held for up to 12 months so nobody can claim it and impersonate the previous owner.

Two features do the practical anti-tracking work. Remote images are proxied anonymously through Fastmail’s own servers by default, so a tracking pixel learns nothing about your location, device or reading habits. Masked Email generates a unique disposable address per service — either on a Fastmail domain or your own — so your real address never circulates; if one starts drawing spam you know exactly which company leaked it, and disabling it affects nothing else. It integrates directly with 1Password and, via API token, with Bitwarden.

One narrow caveat on that alias privacy, reported publicly by a user in 2023 rather than disclosed by the vendor: Fastmail’s X-Resolved-To header can expose the account’s real primary address when mail sent to an alias or Masked Email address is forwarded on as a raw original attachment, and support’s eventual position was that the header cannot be stripped in that workflow. It is specific to forwarding-as-attachment, not a general leak, but it is a real seam in the alias model for anyone who forwards that way.

Features

The addressing system is the strongest part of the product. Up to 100 custom domains per account, with individual addresses and catch-all wildcards on each, and you can buy a domain through Fastmail directly once you have been a paying customer for seven days. On top of ordinary aliases sits Masked Email as a separate layer — unlimited auto-generated, disposable-by-design addresses in the dog.food3495@domain.tld shape, managed from within Fastmail or from 1Password and Bitwarden, with a third-party iOS app, Fastmask, available for managing them outside Fastmail’s own app.

Mail arrives bundled with calendars (personal and work), contacts and file storage, with the calendar and contacts data syncing through the same infrastructure as mail. Scheduled Send, Snooze, per-message private memos, mail rules, VIP notification prioritization, dark mode and themes, and migration tooling for moving in from another provider round out the standard set.

The openness story is partial but real, and it sits at the infrastructure layer rather than the product layer. Fastmail’s commercial service and its client apps are proprietary. But Fastmail is the primary maintainer of Cyrus, the IMAP/JMAP/CardDAV/CalDAV mail-storage server that actually runs its infrastructure — originally a Carnegie Mellon project, now deployed well beyond Fastmail itself. It built and maintains Squire, the open-source HTML5 rich-text editor behind its compose window and adopted by other webmail projects, and Overture JS, the framework its web app is built on, plus smaller pieces like the Hopscotch image proxy and an email-authentication milter. On standards, Fastmail participates in the IETF, M3AAWG and CalConnect, and is the primary designer behind JMAP (RFC 8620), the modern sync protocol intended to succeed IMAP. That is more substantive contribution than most closed-source providers manage, but none of it makes the service itself auditable or reproducibly buildable.

Third-party PGP and S/MIME remain available through external clients, which is Fastmail’s stated answer for anyone who needs message-level encryption. Full IMAP, POP and SMTP support means those clients work without friction.

Spam filtering begins before a message is accepted: Fastmail blocks connections from infrastructure it has identified as spam-sending, based on long-term analysis of bot behavior at the SMTP layer. Messages that get through are content-scored and routed to Spam above a threshold, and the filter adapts per user — reporting spam, marking not-spam, deleting from Spam permanently, archiving from the inbox all train it over time. This requires reading message bodies server-side, which is consistent with a provider that holds the keys and never claimed otherwise.

Usability

Platform coverage is complete: native apps for Windows, macOS (separate Apple Silicon and Intel builds), Linux through Flathub, iOS and Android, plus a full web app. All five support offline reading, drafting, searching and managing across mail, calendar and contacts — not a cached-inbox approximation but the working set available without a connection. Search in particular is fast because the server indexes plaintext, which is the direct functional dividend of the encryption decision.

Account recovery is conventional, and in this category that is a feature rather than a shortcoming. A forgotten password is reset through a recovery email or phone number on file, usernames are recoverable the same way, and lost two-factor devices can be replaced through the same tool. A reset attempted from an unrecognized device, browser or location triggers a 24-hour waiting period as an account-takeover defense. Nobody loses a decade of mail to a misplaced passphrase here — there is no cryptographic dead end because there is no user-held key to lose. That safety net is the flip side of provider-held keys, and for most people it is the trade they would actually choose if asked plainly.

The Masked Email integrations with 1Password and Bitwarden are the detail that makes the feature stick. Generating a fresh masked address at signup time, inside the password manager already filling the form, removes the step where most alias systems quietly fall out of use.

Price & Value

There is no free tier. A 30-day trial runs without a credit card, then converts to paid or lapses, and that is the entire free surface.

Individual is US$5 a month, billed either monthly or as US$60 for twelve. Annual billing carries no discount — the effective rate is identical either way, which is unusual and worth stating plainly rather than spinning. It buys 50 GB for mail, calendar and contacts plus 10 GB of file storage, unlimited addresses on your own domains, Masked Email, personal and work calendars, offline support, Scheduled Send, Snooze, private memos, full IMAP/POP/SMTP access and 24/7 human support.

Duo is US$8 a month (US$96 a year) for two separate private inboxes with 120 GB between them, adding shared calendars and address books alongside each person’s private ones, plus admin tools over the second account’s storage and security. Family is US$11 a month (US$132 a year) for up to six private inboxes and up to 360 GB, at a flat rate whether you fill two slots or all six — which makes the per-person cost fall to under US$2 a month for a household that uses it fully. Prices exclude tax, plans change or cancel at any time, and there is no contract.

Every tier includes encryption at rest and in transit, no ads or tracking, EU or US data residency, up to 100 custom domains, the spam filtering described above, migration tooling and the JMAP-based sync.

Pros and Cons

Independent and employee-owned since 1999 — no venture backing and no parent conglomerate whose priorities could change the product
Australian Privacy Principle 6 legally forbids disclosing data directly to foreign authorities; requests must come through Australian law-enforcement channels
Transparency report is itemised by year, by requesting authority and by data type — 16 valid requests and 5 actioned in 2025, 33 and 16 in 2021
Owns and operates its own physical servers in Amsterdam, Philadelphia and St Louis rather than renting cloud capacity
Public bug bounty Hall of Fame running since 2014 names each researcher, vulnerability class and payout, including $3,750 and $2,000 bounties in 2026
Masked Email generates unlimited disposable per-service addresses with direct 1Password and Bitwarden integration, and remote images are proxied by default
Up to 100 custom domains per account with catch-all addressing on each
Native apps on Windows, macOS, Linux, iOS and Android with genuine offline mail, calendar and contacts support
Standard account recovery with a 24-hour hold on resets from unrecognised devices — no permanent data loss from a forgotten secret

No end-to-end encryption in any Fastmail app, and the company states it does not intend to build it
Fastmail retains sole control of all encryption keys and processes unencrypted content server-side for search, previews and spam scanning
No automatic encryption between two Fastmail accounts; PGP and S/MIME require third-party clients and manual key management
The claimed "external audits by vendors" and penetration tests name no auditor, carry no date, and have no published report
EU data residency is partial — backups for every account sit in Philadelphia, logs consolidate in the US, and some metadata replicates to all sites globally
Choosing the EU region changes nothing about jurisdiction; an Australian company answers Australian legal process either way
No free tier at all — only a 30-day trial
Annual billing carries no discount over monthly, so a twelve-month commitment buys nothing extra
The X-Resolved-To header can expose the real primary address when alias mail is forwarded as a raw attachment, and support states it cannot be stripped

Our Rating

Fastmail fits someone who wants a fast, mature, heavily featured mailbox from a company whose trust signals are structural rather than cryptographic — independent employee ownership, a jurisdiction that blocks direct foreign demands, self-operated hardware, and a transparency report with real numbers in it — and who is content to run PGP through a separate client or skip message encryption entirely. It fits you poorly if zero-access storage is the requirement, because Fastmail holds the keys by design, argues publicly that in-browser E2EE is security theatre, and will not be changing its mind.

Security6.5/10
TLS 1.3 with PFS since 2012, HSTS, strict CSP, U2F/passkey 2FA, and a twelve-year public bug bounty track record are genuine strengths, but Fastmail holds all encryption keys itself, deliberately builds no end-to-end encryption, and its claimed external audits and penetration tests name no auditor, date, or published report
Privacy & Trust6.5/10
Australian Privacy Principle 6 blocks direct foreign disclosure and the itemised multi-year transparency report is a genuinely strong structural signal, backed by independent employee ownership, but the new EU data-residency option still routes backups, logs and some metadata through the US, and the jurisdiction itself doesn't change regardless of region chosen
Features7.0/10
Up to 100 custom domains with catch-all aliasing, unlimited Masked Email addresses with password-manager integrations, and a real (if partial) open-source contribution at the infrastructure layer via Cyrus and JMAP, offset by no built-in E2EE and no automatic encryption between Fastmail accounts
Usability8.0/10
Full native coverage across Windows, macOS, Linux, iOS and Android with genuine offline mail, calendar and contacts access, fast server-side search as a direct benefit of the encryption trade-off, and a conventional account-recovery model with no risk of permanent lockout from a forgotten secret
Price & Value6.0/10
Individual at $5/month and Family at $11/month for up to six inboxes are reasonable for the feature set, but there is no free tier beyond a 30-day trial and annual billing carries no discount over paying monthly

Overall6.8/10

Security 30% · Privacy & Trust 30% · Features 15% · Usability 15% · Price & Value 10%

See our rating methodology →