Updated 16 October 2026 · Edited by the Benchmark Buyer team · How we review
We do the homework you'd do before buying, so you don't have to. Like any careful buyer, we read the independent security audits, the expert reviews and what users say, then sum up where they agree and where they don't. We don't run our own tests. There are no standard test labs for email, so this guide draws on 2 recent independent security assessments and 7 expert reviews and recommendation lists published between June 2025 and September 2026.
The short answer
Proton Mail and Tuta are joint top picks. Proton Mail is the most common first choice among expert sources, and Tuta is the only service on every list we read, with its encryption backed by a 2026 university analysis. Mailbox is a close third, and the best fit if you want a full email suite that works with ordinary mail apps. Proton Mail and Tuta both have free plans.
Stars show the consensus score out of 10, turned into a 5-star scale and rounded to the nearest half star; the exact score is in each product's section. The security checks column sums up independent audits from the last 18 months. Where we couldn't find one, the score rests on expert opinion alone rather than being marked down. We've left out a popularity column because half these services have no Android app of their own to measure.
1. Proton Mail: the experts' usual first choice
★★★★★Consensus score: 9.6
Proton Mail is first at TechRadar, The New Oil, Cloudwards, All About Cookies and CyberInsider, and is one of Privacy Guides' three recommended providers. It is run from Switzerland and publishes its app source code. Its last public security audit was by Securitum in 2021, which is too old for us to count, so its score comes from expert opinion only.
"Proton Mail is one of the best secure email products available." (TechRadar)
Cloudwards goes further: "Proton Mail is the most secure email provider and most private email option on this list for several reasons." (Cloudwards)
Proton's own transparency report says it received 9,301 Swiss legal orders for Proton Mail in 2025, complied with 8,313 and contested 988. It says emails are encrypted and it has no means to decrypt them. (Proton)
Where opinions differ: Android Authority leaves Proton Mail out of its list. Germany's Stiftung Warentest marked down Proton's free plan on ease of use because it lacks IMAP, so it doesn't work directly with ordinary mail apps; paid plans need Proton's Bridge add-on for that.
Who it suits: most people who want private email, especially if you'd also use Proton's VPN, password manager or cloud storage.
2. Tuta: on every list, with independently analysed encryption
★★★★★Consensus score: 9.6
Tuta (formerly Tutanota) is the only service on all seven expert lists. It is a Privacy Guides recommendation, second at The New Oil and Cloudwards, and TechRadar's pick for free users. In August 2026 researchers at the University of Wuppertal published a formal analysis of TutaCrypt, Tuta's encryption system. They reported no vulnerability and concluded "that the protocol provides meaningful post-quantum confidentiality guarantees" (CyberInsider), meaning it is designed to resist future quantum computers. They also noted limits: the quantum protection covers attackers who record traffic, not ones who tamper with it, and it lacks some forms of forward secrecy found in messaging apps. Tuta is based in Germany and publishes its source code.
TechRadar says it offers "exceptional security and privacy to its users, even at the free tier" (TechRadar).
Where opinions differ: Tuta doesn't use the PGP standard, so encrypted mail from people outside Tuta arrives through a temporary Tuta mailbox instead (Privacy Guides). Stiftung Warentest gave its paid plan the weakest ease-of-use mark in its test because it has no IMAP access for ordinary mail apps.
Who it suits: people who want strong encryption on a free plan and are happy to use Tuta's own apps.
3. Mailbox: the full suite that works with any app
★★★★½Consensus score: 9.1
Mailbox (formerly Mailbox.org) is a Privacy Guides recommendation and second at TechRadar, which names it best for green energy. It is based in Berlin. In January 2026 its operator received a BSI C5 Type 1 attestation, an independent check against the German federal cyber security agency's security criteria for cloud services (Mailbox). The announcement doesn't say exactly what the check covered.
"Mailbox Mail (formerly Mailbox.org) is an email service with a focus on being secure, ad-free, and powered by 100% eco-friendly energy." (Privacy Guides)
In Germany's Stiftung Warentest email test (September 2026), Mailbox Light scored 1.8, second best of the 18 plans tested on the German school-grade scale, where lower is better.
Where opinions differ: Cloudwards ranks it only 11th, and The New Oil lists it as an honourable mention. Privacy Guides notes it doesn't encrypt your address book or calendar.
Who it suits: people who want private email, calendar and storage that work with the mail apps they already use.
Mailfence, based in Belgium, is third at Cloudwards and CyberInsider and one of Android Authority's picks, but only three of the seven sources list it, which lowers its score. We found no recent public security audit, so its score rests on expert opinion.
"Mailfence firmly believes that privacy is a right, not a feature." (Android Authority)
Cloudwards highlights password-protected messages: "With Mailfence, you can send encrypted messages that can be accessed with a password." (Cloudwards)
Who it suits: people who want PGP-encrypted email plus documents, calendar and contacts that sync with other apps.
StartMail is second at CyberInsider and one of Android Authority's picks, but eighth at Cloudwards. It is based in the Netherlands. We found no recent public security audit.
"StartMail is based in the Netherlands, which is a good jurisdiction for privacy." (CyberInsider)
Android Authority says it is "best known for its unlimited disposable addresses" (Android Authority).
Who it suits: people who want a separate throwaway address for every sign-up.
Posteo is an honourable mention at The New Oil, sixth at CyberInsider and seventh at Cloudwards. It doesn't appear in the other four lists. It had the best overall result, 1.7, in Stiftung Warentest's September 2026 email test, which weighs ease of use more heavily than privacy. We found no recent public security audit.
"Posteo is another German email service that prioritizes privacy and security, similar to Mailbox.org." (CyberInsider)
Who it suits: people who want simple, ad-free private email at low cost.
Zoho Mail appears in four expert lists, but it is a business suite. All About Cookies says: "Zoho Mail is part of the Zoho Workplace, a suite of products aimed primarily at businesses." This guide covers personal email.
Hushmail, Runbox, Kolab Now and Soverin each appear in only two of the seven lists. We need three to rank a service.
PreVeil, CounterMail, Fastmail, Librem Mail and Thexyz appear in only one list each.
Skiff no longer exists. It announced in February 2024 that it would shut down six months after Notion bought it (Reclaim The Net).
How we score
We don't run our own tests. Each service's consensus score combines three things:
Independent security audits (30%): published security audits, formal analyses or certifications from the last 18 months. A pass with no issues reported scores 100; a pass with limits noted scores 90; issues found score lower. When we can't find a recent audit, we don't mark the service down: its score is worked out from the other two parts alone.
Expert rankings (50%): each service's position in 7 expert lists, from Privacy Guides, TechRadar, Android Authority, The New Oil, Cloudwards, All About Cookies and CyberInsider. Being on an unranked recommendation list counts the same as a top-three place.
Breadth of agreement (20%): how many of those 7 lists include the service.
To be ranked, a service needs a place in at least three expert lists. Scores are capped at 9.9. We leave out evidence older than 18 months; for example, Cybernews' list was last updated in November 2024, and Proton's last public audit dates from 2021, so neither is counted. Stiftung Warentest's results are mentioned for context but not scored, because most of its grades are behind a paywall. Affiliate commission plays no part in the score.
Evidence last checked: 16 October 2026. Full details on how we review.