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Fastmail alternatives: 6 apps ranked by verified data

Facts checked Oct 25, 2026AppBreakup editorialHow we rank

Common reasons people leave Fastmail: no free plan, and not end-to-end encrypted. We ranked 6 alternatives by how directly each one replaces Fastmail, then by reviews, real visits and how recently each app's facts were checked against its own website. Proton Mail currently ranks first.

Quick comparison

#AppPricingOpen sourcePlatformsVerified factsScore
1Proton Mail logoProton MailFree plan + paidYesWeb, Windows, macOS +35 of 566.5
2HEY logoHEYPaidNoWeb, macOS, Windows +35 of 562.6
3Zoho Mail logoZoho MailFree plan + paidNoWeb, Windows, macOS +34 of 459.6
4mailbox.org logomailbox.orgPaidNoWeb4 of 457.2
5Posteo logoPosteoPaidNoWeb4 of 455.3
6StartMail logoStartMailPaidNoWeb, iOS, Android4 of 453.6
  1. Proton Mail logo

    1. Proton MailTop pick

    Best for: Privacy-minded people and teams who want encrypted email without running servers

    Free plan + paidOpen sourceWeb, Windows, macOS, Linux, iOS, Android

    66.5

    score / 100

    Why switch from Fastmail

    Adds end-to-end encryption and a free plan, at the cost of IMAP convenience.

    Pros

    • End-to-end and zero-access encryption by default
    • Open-source, audited apps on every major platform
    • Bundles with Proton VPN, Drive, Calendar and Pass

    Cons

    • Free plan has little storage and one address
    • Search and third-party integrations are more limited than Gmail
    • Using desktop clients needs the paid Bridge app
    Visit Proton Mail Details and reviews
    How this score is calculated
    Editorial fit ×0.3100
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Proton Mail a good Fastmail alternative?

    Verified facts

    5 of 5 verified
    Free plan
    Yes
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Mail Plus price
    $4.99/month, or $3.99/month billed yearly
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Jurisdiction
    Switzerland
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Open source
    Yes, independently audited
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    License (web clients)
    GPL-3.0
    Checked Oct 25, 2026github.com(opens source in a new tab)
  2. HEY logo

    2. HEY

    Best for: People who want to opt in to who can email them and enjoy an opinionated workflow

    PaidWeb, macOS, Windows, Linux, iOS, Android

    62.6

    score / 100

    Why switch from Fastmail

    Another paid, independent service with an opinionated inbox design.

    Pros

    • Screener stops unwanted first-time senders
    • Blocks spy pixels and separates newsletters and receipts
    • Apps on every platform including Linux

    Cons

    • No IMAP, so you must use HEY's own apps
    • Opinionated design that some people find restrictive
    • No free plan after the trial
    Visit HEY Details and reviews
    How this score is calculated
    Editorial fit ×0.387
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is HEY a good Fastmail alternative?

    Verified facts

    5 of 5 verified
    HEY for You price
    $99 per year
    Checked Oct 25, 2026hey.com(opens source in a new tab)
    Free trial
    30 days
    Checked Oct 25, 2026hey.com(opens source in a new tab)
    HEY for Domains price
    $12 per user/month
    Checked Oct 25, 2026hey.com(opens source in a new tab)
    Owner
    37signals
    Checked Oct 25, 2026hey.com(opens source in a new tab)
    Screener
    Yes
    Checked Oct 25, 2026hey.com(opens source in a new tab)
  3. Zoho Mail logo

    3. Zoho Mail

    Best for: Small businesses that want cheap, ad-free email on their own domain

    Free plan + paidWeb, Windows, macOS, Linux, iOS, Android

    59.6

    score / 100

    Why switch from Fastmail

    Cheaper business email on your own domain, with a free plan for small teams.

    Pros

    • Free plan for a few users on a custom domain
    • Much cheaper than Google Workspace or Microsoft 365
    • Ties into Zoho CRM and the rest of the Zoho suite

    Cons

    • Free plan lacks IMAP and has limited storage
    • Interface feels crowded
    • Fewer third-party integrations than Google or Microsoft
    Visit Zoho Mail Details and reviews
    How this score is calculated
    Editorial fit ×0.377
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Zoho Mail a good Fastmail alternative?

    Verified facts

    4 of 4 verified
    Free plan
    Up to 5 users
    Checked Oct 25, 2026zoho.com(opens source in a new tab)
    Free plan storage
    5 GB per user, one domain
    Checked Oct 25, 2026zoho.com(opens source in a new tab)
    Encryption
    TLS, S/MIME, AES-256 at rest
    Checked Oct 25, 2026zoho.com(opens source in a new tab)
    Business customers
    550,000+
    Checked Oct 25, 2026zoho.com(opens source in a new tab)
  4. mailbox.org logo

    4. mailbox.org

    Best for: European individuals and businesses who want private email and office tools in one place

    PaidWeb

    57.2

    score / 100

    Why switch from Fastmail

    A European provider with similar standards support and an office suite.

    Pros

    • Low per-user prices with custom domains
    • Data stored in Germany with PGP options
    • Includes calendar, cloud storage, office suite and meetings

    Cons

    • Web interface feels dated
    • No dedicated mobile apps
    • No free plan
    Visit mailbox.org Details and reviews
    How this score is calculated
    Editorial fit ×0.369
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is mailbox.org a good Fastmail alternative?

    Verified facts

    4 of 4 verified
    Light plan
    €1 per user/month (2 GB)
    Checked Oct 25, 2026mailbox.org(opens source in a new tab)
    Standard plan
    €4 per user/month (20 GB)
    Checked Oct 25, 2026mailbox.org(opens source in a new tab)
    Free trial
    30 days
    Checked Oct 25, 2026mailbox.org(opens source in a new tab)
    Data location
    Germany
    Checked Oct 25, 2026mailbox.org(opens source in a new tab)
  5. Posteo logo

    5. Posteo

    Best for: People who want cheap, private email that works with any standard mail app

    PaidWeb

    55.3

    score / 100

    Why switch from Fastmail

    A much cheaper, no-frills provider with anonymous sign-up.

    Pros

    • Very low fixed price with no ads
    • Anonymous sign-up and payment
    • Standard protocols, so any mail and calendar app works

    Cons

    • No custom domains
    • Plain web interface and no own mobile apps
    • No free plan
    Visit Posteo Details and reviews
    How this score is calculated
    Editorial fit ×0.363
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Posteo a good Fastmail alternative?

    Verified facts

    4 of 4 verified
    Price
    1 EUR per month
    Checked Oct 25, 2026posteo.de(opens source in a new tab)
    Storage
    4 GB, upgradeable
    Checked Oct 25, 2026posteo.de(opens source in a new tab)
    Anonymous sign-up
    Yes
    Checked Oct 25, 2026posteo.de(opens source in a new tab)
    Included apps
    Email, address book, calendar, notes
    Checked Oct 25, 2026posteo.de(opens source in a new tab)
  6. StartMail logo

    6. StartMail

    Best for: People who want private email with lots of aliases and simple encryption

    PaidWeb, iOS, Android

    53.6

    score / 100

    Why switch from Fastmail

    Private email with unlimited aliases, based in the Netherlands.

    Pros

    • Unlimited aliases on all plans
    • Password-protected encrypted email to anyone
    • IMAP support for any mail app

    Cons

    • No free plan
    • Fewer features and add-on services than Proton
    • Stored mail not end-to-end encrypted by default
    Visit StartMail Details and reviews
    How this score is calculated
    Editorial fit ×0.357
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is StartMail a good Fastmail alternative?

    Verified facts

    4 of 4 verified
    Personal plan
    $59.88 per year
    Checked Oct 25, 2026startmail.com(opens source in a new tab)
    Free trial
    7 days
    Checked Oct 25, 2026startmail.com(opens source in a new tab)
    Aliases
    Unlimited
    Checked Oct 25, 2026startmail.com(opens source in a new tab)
    Jurisdiction
    Netherlands
    Checked Oct 25, 2026startmail.com(opens source in a new tab)

The best Fastmail alternative for…

The highest-ranked app in this list for each need.

Proton Mail logo

Best Fastmail alternative for most people

Proton Mail

Adds end-to-end encryption and a free plan, at the cost of IMAP convenience.

Zoho Mail logo

Best Fastmail alternative for a free plan you can upgrade

Zoho Mail

Cheaper business email on your own domain, with a free plan for small teams.

Proton Mail logo

Best Fastmail alternative for open source

Proton Mail

Adds end-to-end encryption and a free plan, at the cost of IMAP convenience.

HEY logo

Best Fastmail alternative for Mac

HEY

Another paid, independent service with an opinionated inbox design.

Proton Mail logo

Best Fastmail alternative for Windows

Proton Mail

Adds end-to-end encryption and a free plan, at the cost of IMAP convenience.

Proton Mail logo

Best Fastmail alternative for Linux

Proton Mail

Adds end-to-end encryption and a free plan, at the cost of IMAP convenience.

StartMail logo

Best Fastmail alternative for iPhone and Android

StartMail

Private email with unlimited aliases, based in the Netherlands.

mailbox.org logo

Best Fastmail alternative for working in the browser

mailbox.org

A European provider with similar standards support and an office suite.

Fastmail alternatives: common questions

What is the best alternative to Fastmail?

Proton Mail ranks first right now. Adds end-to-end encryption and a free plan, at the cost of IMAP convenience. HEY and Zoho Mail follow it in our ranking.

Is there a free alternative to Fastmail?

Yes. Proton Mail (free plan + paid) and Zoho Mail (free plan + paid) have a free option. Check each app's verified facts for current plan limits.

Is there an open-source alternative to Fastmail?

Yes: Proton Mail.

Which Fastmail alternatives work on Linux?

Proton Mail, HEY and Zoho Mail run on Linux.

Why do people switch from Fastmail?

The complaints we hear most: no free plan; not end-to-end encrypted; no desktop apps of its own.

How is this list ranked?

Every app is scored with the same published formula: how directly it replaces Fastmail, reviews (weighted by verification), visits from AppBreakup, how recently its facts were checked against its own website, and reader votes.