--- title: "Is Mailfence Safe? Its Encryption Is Opt-In, Not Default" date: "2026-11-12" author: "Ahsan Luqman" canonical_url: "https://aliasfleet.com/blog/is-mailfence-safe" tags: ["Email Privacy", "Secure Email", "Mailfence"] description: "Mailfence promises no one can read mail, not even Mailfence. The claim holds only for mail encrypted with OpenPGP, switched on message by message." --- # Is Mailfence Safe? Its Encryption Is Opt-In, Not Default Mailfence promises no one can read mail, not even Mailfence. The claim holds only for mail encrypted with OpenPGP, switched on message by message. Mailfence is a Belgian email service run by ContactOffice Group SA, and the safety question has two answers. OpenPGP-encrypted mail cannot be read by Mailfence, because the browser does the encryption and the decryption, and the private key is stored on Mailfence servers encrypted with the account holder passphrase, with Mailfence holding no root key. Mail that goes out without that step remains readable on Mailfence servers in Belgium, where a valid Belgian court order can force its disclosure. The record shows this happening: 21 requests arrived in the second half of 2025, and 9 were complied with. ## The claim and the default state The [private email page](https://mailfence.com/en/private-email.jsp) says that no one can read encrypted emails, not even Mailfence, because the browser encrypts each message and only the intended recipient decrypts it. The wording is accurate, and one word sets its boundary: encrypted. It describes mail that has been encrypted, and it covers nothing else in the account. Nothing encrypts by default. A new account sends ordinary mail until the holder configures OpenPGP, creates or imports a key pair, and then picks the encrypted option message by message. The two choices appear side by side at send time in webmail, encrypted or in the clear. A [critique of the claim](https://kaifisahil.substack.com/p/dissecting-mailfences-security-claims) puts it plainly: the promise is technically correct, and it depends on a manual setup that, the critique claims without a source, most account holders never finish. The percentage in that critique comes with no source. The setup mechanism itself is confirmed by Mailfence documentation. ## OpenPGP encryption OpenPGP is the encryption standard behind the claim. It is defined in [RFC 4880](https://www.rfc-editor.org/rfc/rfc4880) of November 2007, which specifies public-key and symmetric cryptography for confidentiality, key management, authentication and digital signatures. The service includes a built-in keystore, so generating and managing keys needs no third-party add-on. A key pair can be created inside Mailfence or imported from another tool. Several key pairs can be held at once, and a message can carry a signature so the recipient can verify where it came from. The browser is where key generation happens. The private key is encrypted locally with the account holder passphrase before it crosses the network, according to an [independent review](https://www.email-tools.me/posts/mailfence-review/). Mailfence states that the stored private key is encrypted with the account holder passphrase using AES-256. The unencrypted private key never appears on Mailfence servers, and Mailfence holds no root key. Under that design, the provider cannot quietly read encrypted mail, and the keys also stay portable, so keys and messages can be exported and used with any OpenPGP tool. In its [comparison with Tuta](https://blog.mailfence.com/tuta-vs-mailfence/), Mailfence notes that OpenPGP mail can be exchanged with any OpenPGP user. Tuta uses a proprietary format and does not support OpenPGP, so encrypted mail cannot leave the Tuta system. OpenPGP on Mailfence has the same limits as OpenPGP anywhere, because both sides must use it for a message to be end-to-end encrypted. A message from Mailfence to a Gmail address travels under TLS, but the recipient holds no PGP key, so it is not end-to-end encrypted. The private key is protected by a passphrase. If the passphrase and the key backup are both lost, the encrypted mail cannot be recovered, by the account holder or by Mailfence. Client-side keys remove the provider's ability to read the mail, and with it the provider's ability to rescue it. ## Unencrypted mail Without OpenPGP, a message travels under TLS and has no further protection once it arrives. The [secure email page](https://mailfence.com/en/secure-email.jsp) states that all connections use TLS encryption, with Perfect Forward Secrecy on HTTPS connections and HSTS on all web pages. Inbound mail is validated with SPF and DKIM. This is baseline practice across the industry, not a feature particular to Mailfence. Once a message reaches Mailfence servers, TLS stops applying. The body is then stored in a form Mailfence can read. The Mailfence [security analysis](https://kb.mailfence.com/kb/mailfence-security-analysis/) describes the split directly. Bodies and attachments encrypted end to end are encrypted in storage with OpenPGP, and the web server does not know them. Sent and draft items are the exception. Message headers in storage are not encrypted at all. Subject lines, sender and recipient addresses, and timestamps sit unencrypted even for mail that is otherwise protected. The analysis also lists the standard limits of browser-based encryption, including false code served in a man-in-the-middle attack and access to the account holder computer. | Property | OpenPGP-encrypted mail | Mail sent without encryption | | :--- | :--- | :--- | | Message body readable by Mailfence | No | Yes | | Subject, sender, recipient and timestamps readable | Yes | Yes | | Protection in transit | TLS plus OpenPGP | TLS only | | Body readable by Mailfence after disclosure | No, stays encrypted | Yes | ## Data collection A long list of items appears in the Mailfence [privacy policy](https://mailfence.com/en/privacy.jsp): IP addresses, message-IDs, sender and recipient addresses, subjects, browser versions, countries and timestamps. Automatic anti-spam, anti-virus and anti-abuse checks run over incoming and outgoing messages. Some card details remain stored after credit card payments. Registration asks for an external email address, used for the activation code and for contact if the account cannot be accessed. The same policy sets out what does not happen to that data. Mailfence does not sell, trade or transfer personally identifiable information to outside parties, except when forced by Belgian law. It does not use Google Analytics trackers. Messages, calendar entries, contacts and documents feed a search index, but the policy states that no information from that index is used to compile profiles of users. Technical and organisational measures behind that position are listed on the [GDPR page](https://smtp.mailfence.com/en/gdpr.jsp). The policy also states retention periods. Backups of deleted messages and documents are kept for 45 days, then permanently deleted. After an account is closed, all data is permanently deleted 30 days after the legal expiration date. Belgian law sets that date at 365 days after account closing. The policy was last updated on 21 December 2021, more than four years before November 2026, and may not reflect current practice in full. ## Belgian jurisdiction and the transparency report ContactOffice Group SA launched Mailfence in November 2013. The company has run hosted collaboration software since 1999, according to [CyberInsider](https://cyberinsider.com/email/reviews/mailfence/). Mailfence is provided by the Belgian company ContactOffice Group SA and falls under Belgian law. Mailfence states that Belgium has no equivalent to the US National Security Letter or gag order, so the company cannot be forced to act without being allowed to disclose it. The company also states that it does not disclose information directly to law enforcement agencies outside Belgium. Belgian courts can compel disclosure, and Mailfence complies when they do. The [transparency report](https://blog.mailfence.com/transparency-report-and-warrant-canary/) gives the numbers. From 1 July 2025 to 31 December 2025, Mailfence received requests for user identification in 21 cases and complied in 9, under valid Belgian court orders. From the launch of Mailfence to 30 June 2025, it received 228 such requests and complied in 105 cases. Only legally binding requests from Belgian courts are counted. Unofficial requests are always rejected and not counted. The transparency page was last updated in January 2026, with the next update due in July 2026. As read in November 2026, it still shows the July to December 2025 period. The figures describe the past, not the present. The same page carries a warrant canary. It states that Mailfence has never received US National Security Letters or FISA court orders, and has never placed backdoors in hardware or software. The sources do not settle whether Belgium imposes a data-retention obligation on email providers. One review states that there is none. CyberInsider reports that the 2016 retention law was declared unconstitutional on 22 April 2021. The privacy policy lists the metadata collected without citing a retention law as the reason, so retention-law logging remains unverified. Belgium is also a member of the Fourteen Eyes alliance, which CyberInsider notes as a drawback. ## Password-encrypted messages A second encrypted option exists for recipients who do not use PGP. The sender and recipient agree a password, which encrypts the message, and the recipient follows a link to decrypt it on Mailfence servers. The decryption takes place on Mailfence servers, not in the recipient browser. Mailfence therefore has the technical ability to decrypt these messages. The protection is not end-to-end encryption in the sense that OpenPGP is, and that follows from Mailfence's own wording. The Substack critique makes this point. ## Pricing and plans The free plan provides 500 MB of email storage and 500 MB of document storage, according to the Mailfence [comparison of free providers](https://blog.mailfence.com/best-free-email-providers/). IMAP and POP access come with paid plans only. Paid plans start at 2.50 EUR per month. The free plan is thin for a primary mailbox, because 500 MB of storage fills quickly and, without IMAP, the account must be used in webmail or the mobile app. The [FAQ](https://imap.mailfence.com/en/faq.jsp) states that 15 percent of Ultra plan revenues go to the Electronic Frontier Foundation and European Digital Rights. Subscriptions are not refunded, because the free plan allows testing before upgrading. Payment options are credit card, Bitcoin, Litecoin, PayPal and wire transfer, and a free account is suspended after 7 months of inactivity and deleted 5 months later. The pricing figures in this section come from the Mailfence blog, because the pricing page returned 404. The code is not open source. CyberInsider lists closed code as a drawback, because the encryption implementation cannot be inspected by the public. Mailfence states that its code is open to audits by recognised security experts, but no audit report was found or verified. ## Mailfence and Posteo [Is Posteo Safe?](https://aliasfleet.com/blog/is-posteo-safe) is the closest published comparison on this site. It covers a German service with the same opt-in encryption shape and a different data model. Posteo collects no personal data at signup and logs no IP addresses, while Mailfence collects IP addresses, subjects and timestamps, and both services still differ sharply in what they record despite both offering OpenPGP. ## AliasFleet and the Mailfence inbox AliasFleet provides managed, persistent forwarding addresses, and a Mailfence account can sit behind them as the destination inbox. Mail sent to an alias forwards to the Mailfence address, and replies travel back through the alias. Websites never receive the Mailfence address itself. The free plan from [AliasFleet](https://aliasfleet.com) includes 10 active aliases. The alias layer changes what is exposed, not what Mailfence can read. Mail forwarded to Mailfence is still mail held by Mailfence, and the encryption split described above still applies to it. An alias keeps the Mailfence address out of circulation. It also lets the account holder cut off a single alias when a service leaks it, as described in [How Email Aliases Actually Work](https://aliasfleet.com/blog/how-email-aliases-actually-work). Banking follows the same separation: a bank account uses a permanent real address kept only for financial accounts, as described in [Should You Use a Separate Email for Banking](https://aliasfleet.com/blog/should-you-use-a-separate-email-for-banking). ## Summary of the findings The OpenPGP implementation is real, standards-based, client-side and portable. The transparency report runs on a six-month cycle, and its figures show real compliance with Belgian court orders. Encryption has to be switched on, per message, by an account holder who has set up keys. The other party has to use PGP as well. Until both steps happen, the mail is TLS mail on Belgian servers, with headers stored unencrypted and metadata collected under a privacy policy last updated on 21 December 2021. The wider question of provider access is covered in [Can My Email Provider Read My Emails](https://aliasfleet.com/blog/can-my-email-provider-read-my-emails), and the check for an address already in a breach is covered in [How to Check If Your Email Was Leaked](https://aliasfleet.com/blog/how-to-check-if-your-email-was-leaked).