privacyguides.org/i18n/zh/email.md

title	icon	description
Email Services	material/email	These email providers offer a great place to store your emails securely, and many offer interoperable OpenPGP encryption with other providers.

电子邮件实际上是使用任何在线服务的必需品，但我们不建议使用它进行人与人之间的对话。 与其使用电子邮件与他人联系，不如考虑使用支持前向保密的即时通讯媒介。

推荐的即时通讯工具{.md-button}

对于其他一切，我们根据可持续的商业模式和内置的安全和隐私功能，推荐各种电子邮件供应商。

• OpenPGP-Compatible Email Providers :material-arrow-right-drop-circle:
• Other Encrypted Providers :material-arrow-right-drop-circle:
• Email Aliasing Services :material-arrow-right-drop-circle:
• Self-Hosted Options :material-arrow-right-drop-circle:

OpenPGP 兼容服务

These providers natively support OpenPGP encryption/decryption and the Web Key Directory (WKD) standard, allowing for provider-agnostic E2EE emails. 例如，Proton Mail用户可以向Mailbox.org用户发送E2EE信息，或者你可以从支持OpenPGP的互联网服务中收到OpenPGP加密的通知。

• { .twemoji } Proton Mail
• { .twemoji } Mailbox.org

!!! 警告

当使用像OpenPGP这样的E2EE技术时，电子邮件仍然会有一些元数据没有在电子邮件的标题中进行加密。 阅读更多关于[电子邮件元数据](basics/email-security.md#email-metadata-overview)。

OpenPGP也不支持转发保密，这意味着如果你或收件人的私钥被盗，所有以前用它加密的信息都会暴露。 [如何保护我的私钥？](basics/email-security.md#how-do-i-protect-my-private-keys)

Proton Mail

!!! recommendation

! [Proton Mail徽标] (assets/img/email/protonmail.svg) {align = right}

* * Proton Mail * *是一项专注于隐私、加密、安全性和易用性的电子邮件服务。 他们自**2013年**以来一直在运作。 Proton公司总部位于瑞士日内瓦。 他们的免费计划中，账户一开始开始有500MB的存储空间。

[:octicons-home-16: 首页](https://proton.me/mail){ .md-button .md-button--primary }
[:simple-torbrowser:](https://protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion){ .card-link title="洋葱服务" }
[:octicons-eye-16:](https://proton.me/legal/privacy){ .card-link title="隐私政策" }
[:octicons-info-16:](https://proton.me/support/mail){ .card-link title="文档"}
[:octicons-code-16:](https://github.com/ProtonMail){ .card-link title="源代码" }

??? 下载

    - [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=ch.protonmail)。 ndroid)
    - [:simple-appstore: App Store](https://apps.apple.com/app/apple-store/id979659905)
    - [:simple-github: GitHub](https://github. om/ProtonMail/proton-mail-android/releases)
    - [:simple-windows11: Windows](https://proton.me/mail/bridge#download)
    - [:simple-apple: macOS](https://proton. e/mail/bridge#download)
    - [:simple-linux: Linux](https://proton.me/mail/bridge#download)
    - [:octicons-browser-16: Web](https://mail.proton.me)

免费账户有一些限制，如不能搜索正文，不能访问 Proton Mail Bridge，这是使用 推荐的桌面电子邮件客户端 （如Thunderbird）所需要的。 付费帐户包括Proton Mail Bridge等功能，额外的存储空间和自定义域支持。 2021年11月9日， Securitum，为Proton Mail的应用程序提供了一份 的证明信。

如果你有 "Proton Unlimited"、" Business "或 "Visionary "计划，你还可以免费获得 SimpleLogin Premium。

Proton Mail有内部碰撞报告，他们 **，不与第三方分享。 这可以在以下方面禁用。 设置 > 转到设置 > 帐户 > 安全和隐私 > 发送崩溃报告。

:material-check:{ .pg-green } Custom Domains and Aliases

Paid Proton Mail subscribers can use their own domain with the service or a catch-all address. Proton Mail also supports subaddressing, which is useful for people who don't want to purchase a domain.

:material-check:{ .pg-green } Private Payment Methods

Proton Mail accepts cash by mail in addition to standard credit/debit card, Bitcoin, and PayPal payments.

:material-check:{ .pg-green } Account Security

Proton Mail supports TOTP two factor authentication and hardware security keys using FIDO2 or U2F standards. The use of a hardware security key requires setting up TOTP two factor authentication first.

:material-check:{ .pg-green } Data Security

Proton Mail has zero-access encryption at rest for your emails and calendars. 使用零访问加密的数据只有你才能访问。

Certain information stored in Proton Contacts, such as display names and email addresses, are not secured with zero-access encryption. 支持零访问加密的联系人字段，如电话号码，会用挂锁图标表示。

:material-check:{ .pg-green } Email Encryption

Proton Mail has integrated OpenPGP encryption in their webmail. 给其他Proton Mail账户的邮件是自动加密的，用OpenPGP密钥给非Proton Mail地址加密可以在账户设置中轻松启用。 They also allow you to encrypt messages to non-Proton Mail addresses without the need for them to sign up for a Proton Mail account or use software like OpenPGP.

Proton Mail also supports the discovery of public keys via HTTP from their Web Key Directory (WKD). 这使得不使用Proton Mail的人可以轻松找到Proton Mail账户的OpenPGP密钥，实现跨供应商的E2EE。

:material-information-outline:{ .pg-blue } Account Termination

If you have a paid account and your bill is unpaid after 14 days, you won't be able to access your data. 30天后，你的账户将成为欠费账户，不会收到来信。 在此期间，您将继续收到账单。

:material-information-outline:{ .pg-blue } Additional Functionality

Proton Mail提供9.99欧元/月的 "无限 "账户，除了提供多个账户、域名、别名和500GB的存储空间外，还能访问Proton VPN。

Proton Mail不提供数字遗留功能。

Mailbox.org

!!! recommendation

![Mailbox.org标志](assets/img/email/mailboxorg.svg){ align=right }

**Mailbox.org**是一个专注于安全、无广告、并由100%环保能源私人提供的电子邮件服务。 他们自2014年以来一直在运作。 Mailbox.org总部位于德国柏林。 账户开始时有2GB的存储空间，可根据需要升级。

[:octicons-home-16: 首页](https://mailbox.org){ .md-button .md-button--primary }
[:octicons-eye-16:](https://mailbox.org/en/data-protection-privacy-policy){ .card-link title="隐私政策" }
[:octicons-info-16:](https://kb.mailbox.org/en/private){ .card-link title="文件"}

?? 下载

    - [:octicons-browser-16: Web](https://login.mailbox.org)

:material-check:{ .pg-green } Custom Domains and Aliases

Mailbox.org lets you use your own domain, and they support catch-all addresses. Mailbox.org also supports subaddressing, which is useful if you don't want to purchase a domain.

:material-check:{ .pg-green } Private Payment Methods

Mailbox.org doesn't accept any cryptocurrencies as a result of their payment processor BitPay suspending operations in Germany. 然而，他们确实接受邮寄现金、向银行账户支付现金、银行转账、信用卡、贝宝和几个德国特有的处理器：Paydirekt和Sofortüberweisung。

:material-check:{ .pg-green } Account Security

Mailbox.org supports two factor authentication for their webmail only. You can use either TOTP or a Yubikey via the Yubicloud. Web standards such as WebAuthn are not yet supported.

:material-information-outline:{ .pg-blue } Data Security

Mailbox.org allows for encryption of incoming mail using their encrypted mailbox. New messages that you receive will then be immediately encrypted with your public key.

However, Open-Exchange, the software platform used by Mailbox.org, does not support the encryption of your address book and calendar. A standalone option may be more appropriate for that information.

:material-check:{ .pg-green } Email Encryption

Mailbox.org has integrated encryption in their webmail, which simplifies sending messages to people with public OpenPGP keys. They also allow remote recipients to decrypt an email on Mailbox.org's servers. This feature is useful when the remote recipient does not have OpenPGP and cannot decrypt a copy of the email in their own mailbox.

Mailbox.org also supports the discovery of public keys via HTTP from their Web Key Directory (WKD). This allows people outside of Mailbox.org to find the OpenPGP keys of Mailbox.org accounts easily, for cross-provider E2EE.

:material-information-outline:{ .pg-blue } Account Termination

Your account will be set to a restricted user account when your contract ends, after 30 days it will be irrevocably deleted.

:material-information-outline:{ .pg-blue } Additional Functionality

You can access your Mailbox.org account via IMAP/SMTP using their .onion service. However, their webmail interface cannot be accessed via their .onion service and you may experience TLS certificate errors.

All accounts come with limited cloud storage that can be encrypted. Mailbox.org also offers the alias @secure.mailbox.org, which enforces the TLS encryption on the connection between mail servers, otherwise the message will not be sent at all. Mailbox.org also supports Exchange ActiveSync in addition to standard access protocols like IMAP and POP3.

Mailbox.org has a digital legacy feature for all plans. You can choose whether you want any of your data to be passed to heirs providing that they apply and provide your testament. Alternatively, you can nominate a person by name and address.

More Providers

These providers store your emails with zero-knowledge encryption, making them great options for keeping your stored emails secure. However, they don't support interoperable encryption standards for E2EE communications between providers.

• { .twemoji }{ .twemoji } StartMail
• { .twemoji } Tutanota

StartMail

!!! recommendation

![StartMail logo](assets/img/email/startmail.svg#only-light){ align=right }
![StartMail logo](assets/img/email/startmail-dark.svg#only-dark){ align=right }

**StartMail** is an email service with a focus on security and privacy through the use of standard OpenPGP encryption. StartMail has been in operation since 2014 and is based in Boulevard 11, Zeist Netherlands. Accounts start with 10GB. They offer a 30-day trial.

[:octicons-home-16: Homepage](https://www.startmail.com/){ .md-button .md-button--primary }
[:octicons-eye-16:](https://www.startmail.com/en/privacy/){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://support.startmail.com){ .card-link title=Documentation}

??? downloads

    - [:octicons-browser-16: Web](https://mail.startmail.com/login)

:material-check:{ .pg-green } Custom Domains and Aliases

Personal accounts can use Custom or Quick aliases. Custom domains are also available.

:material-alert-outline:{ .pg-orange } Private Payment Methods

StartMail accepts Visa, MasterCard, American Express and Paypal. StartMail also has other payment options such as Bitcoin (currently only for Personal accounts) and SEPA Direct Debit for accounts older than a year.

:material-check:{ .pg-green } Account Security

StartMail supports TOTP two factor authentication for webmail only. They do not allow U2F security key authentication.

:material-information-outline:{ .pg-blue } Data Security

StartMail has zero access encryption at rest, using their "user vault" system. When you log in, the vault is opened, and the email is then moved to the vault out of the queue where it is decrypted by the corresponding private key.

StartMail supports importing contacts however, they are only accessible in the webmail and not through protocols such as CalDAV. Contacts are also not stored using zero knowledge encryption.

:material-check:{ .pg-green } Email Encryption

StartMail has integrated encryption in their webmail, which simplifies sending encrypted messages with public OpenPGP keys. However, they do not support the Web Key Directory standard, making the discovery of a Startmail mailbox's public key more challenging for other email providers or clients.

:material-information-outline:{ .pg-blue } Account Termination

On account expiration, StartMail will permanently delete your account after 6 months in 3 phases.

:material-information-outline:{ .pg-blue } Additional Functionality

StartMail allows for proxying of images within emails. If you allow the remote image to be loaded, the sender won't know what your IP address is.

StartMail does not offer a digital legacy feature.

Tutanota

!!! recommendation

![Tutanota logo](assets/img/email/tutanota.svg){ align=right }

**Tutanota** is an email service with a focus on security and privacy through the use of encryption. Tutanota has been in operation since **2011** and is based in Hanover, Germany. Accounts start with 1GB storage with their free plan.

[:octicons-home-16: Homepage](https://tutanota.com){ .md-button .md-button--primary }
[:octicons-eye-16:](https://tutanota.com/privacy){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://tutanota.com/faq){ .card-link title=Documentation}
[:octicons-code-16:](https://github.com/tutao/tutanota){ .card-link title="Source Code" }
[:octicons-heart-16:](https://tutanota.com/community/){ .card-link title=Contribute }

??? downloads

    - [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=de.tutao.tutanota)
    - [:simple-appstore: App Store](https://apps.apple.com/app/tutanota/id922429609)
    - [:simple-github: GitHub](https://github.com/tutao/tutanota/releases)
    - [:simple-windows11: Windows](https://tutanota.com/#download)
    - [:simple-apple: macOS](https://tutanota.com/#download)
    - [:simple-linux: Linux](https://tutanota.com/#download)
    - [:octicons-browser-16: Web](https://mail.tutanota.com/)

Tutanota doesn't support the IMAP protocol or the use of third-party email clients, and you also won't be able to add external email accounts to the Tutanota app. Neither Email import or subfolders are currently supported, though this is due to be changed. Emails can be exported individually or by bulk selection per folder, which may be inconvenient if you have many folders.

:material-check:{ .pg-green } Custom Domains and Aliases

Paid Tutanota accounts can use up to 5 aliases and custom domains. Tutanota doesn't allow for subaddressing (plus addresses), but you can use a catch-all with a custom domain.

:material-information-outline:{ .pg-blue } Private Payment Methods

Tutanota only directly accepts credit cards and PayPal, however cryptocurrency can be used to purchase gift cards via their partnership with Proxystore.

:material-check:{ .pg-green } Account Security

Tutanota supports two factor authentication with either TOTP or U2F.

:material-check:{ .pg-green } Data Security

Tutanota has zero access encryption at rest for your emails, address book contacts, and calendars. This means the messages and other data stored in your account are only readable by you.

:material-information-outline:{ .pg-blue } Email Encryption

Tutanota does not use OpenPGP. Tutanota accounts can only receive encrypted emails from non-Tutanota email accounts when sent via a temporary Tutanota mailbox.

:material-information-outline:{ .pg-blue } Account Termination

Tutanota will delete inactive free accounts after six months. You can reuse a deactivated free account if you pay.

:material-information-outline:{ .pg-blue } Additional Functionality

Tutanota offers the business version of Tutanota to non-profit organizations for free or with a heavy discount.

Tutanota also has a business feature called Secure Connect. This ensures customer contact to the business uses E2EE. The feature costs €240/y.

Tutanota doesn't offer a digital legacy feature.

Email Aliasing Services

An email aliasing service allows you to easily generate a new email address for every website you register for. The email aliases you generate are then forwarded to an email address of your choosing, hiding both your "main" email address and the identity of your email provider. True email aliasing is better than plus addressing commonly used and supported by many providers, which allows you to create aliases like yourname+[anythinghere]@example.com, because websites, advertisers, and tracking networks can trivially remove anything after the + sign to know your true email address.

• { .twemoji } mailcow
• { .twemoji } Mail-in-a-Box

Email aliasing can act as a safeguard in case your email provider ever ceases operation. In that scenario, you can easily re-route your aliases to a new email address. In turn, however, you are placing trust in the aliasing service to continue functioning.

Using a dedicated email aliasing service also has a number of benefits over a catch-all alias on a custom domain:

• Aliases can be turned on and off individually when you need them, preventing websites from emailing you randomly.
• Replies are sent from the alias address, shielding your real email address.

They also have a number of benefits over "temporary email" services:

• Aliases are permanent and can be turned on again if you need to receive something like a password reset.
• Emails are sent to your trusted mailbox rather than stored by the alias provider.
• Temporary email services typically have public mailboxes which can be accessed by anyone who knows the address, aliases are private to you.

Our email aliasing recommendations are providers that allow you to create aliases on domains they control, as well as your own custom domain(s) for a modest yearly fee. They can also be self-hosted if you want maximum control. However, using a custom domain can have privacy-related drawbacks: If you are the only person using your custom domain, your actions can be easily tracked across websites simply by looking at the domain name in the email address and ignoring everything before the at (@) sign.

Using an aliasing service requires trusting both your email provider and your aliasing provider with your unencrypted messages. Some providers mitigate this slightly with automatic PGP encryption, which reduces the number of parties you need to trust from two to one by encrypting incoming emails before they are delivered to your final mailbox provider.

AnonAddy

!!! recommendation

![AnonAddy logo](assets/img/email/anonaddy.svg#only-light){ align=right }
![AnonAddy logo](assets/img/email/anonaddy-dark.svg#only-dark){ align=right }

**AnonAddy** lets you create 20 domain aliases on a shared domain for free, or unlimited "standard" aliases which are less anonymous.

[:octicons-home-16: Homepage](https://anonaddy.com){ .md-button .md-button--primary }
[:octicons-eye-16:](https://anonaddy.com/privacy/){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://app.anonaddy.com/docs/){ .card-link title=Documentation}
[:octicons-code-16:](https://github.com/anonaddy){ .card-link title="Source Code" }
[:octicons-heart-16:](https://anonaddy.com/donate/){ .card-link title=Contribute }

??? downloads

    - [:simple-android: Android](https://anonaddy.com/faq/#is-there-an-android-app)
    - [:material-apple-ios: iOS](https://anonaddy.com/faq/#is-there-an-ios-app)
    - [:simple-firefoxbrowser: Firefox](https://addons.mozilla.org/en-GB/firefox/addon/anonaddy/)
    - [:simple-googlechrome: Chrome](https://chrome.google.com/webstore/detail/anonaddy-anonymous-email/iadbdpnoknmbdeolbapdackdcogdmjpe)

The number of shared aliases (which end in a shared domain like @anonaddy.me) that you can create is limited to 20 on AnonAddy's free plan and 50 on their $12/year plan. You can create unlimited standard aliases (which end in a domain like @[username].anonaddy.com or a custom domain on paid plans), however, as previously mentioned, this can be detrimental to privacy because people can trivially tie your standard aliases together based on the domain name alone. Unlimited shared aliases are available for $36/year.

Notable free features:

• 20 Shared Aliases
• Unlimited Standard Aliases
• No Outgoing Replies
• 2 Recipient Mailboxes
• Automatic PGP Encryption

SimpleLogin

!!! recommendation

![Simplelogin logo](assets/img/email/simplelogin.svg){ align=right }

**SimpleLogin** is a free service which provides email aliases on a variety of shared domain names, and optionally provides paid features like unlimited aliases and custom domains.

[:octicons-home-16: Homepage](https://simplelogin.io){ .md-button .md-button--primary }
[:octicons-eye-16:](https://simplelogin.io/privacy/){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://simplelogin.io/docs/){ .card-link title=Documentation}
[:octicons-code-16:](https://github.com/simple-login){ .card-link title="Source Code" }

??? downloads

    - [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=io.simplelogin.android)
    - [:simple-appstore: App Store](https://apps.apple.com/app/id1494359858)
    - [:simple-github: GitHub](https://github.com/simple-login/Simple-Login-Android/releases)
    - [:simple-firefoxbrowser: Firefox](https://addons.mozilla.org/en-US/firefox/addon/simplelogin/)
    - [:simple-googlechrome: Chrome](https://chrome.google.com/webstore/detail/dphilobhebphkdjbpfohgikllaljmgbn)
    - [:simple-microsoftedge: Edge](https://microsoftedge.microsoft.com/addons/detail/simpleloginreceive-sen/diacfpipniklenphgljfkmhinphjlfff)
    - [:simple-safari: Safari](https://apps.apple.com/app/id1494051017)

SimpleLogin was acquired by Proton AG as of April 8, 2022. If you use Proton Mail for your primary mailbox, SimpleLogin is a great choice. As both products are now owned by the same company you now only have to trust a single entity. We also expect that SimpleLogin will be more tightly integrated with Proton's offerings in the future. SimpleLogin continues to support forwarding to any email provider of your choosing. Securitum audited SimpleLogin in early 2022 and all issues were addressed.

You can link your SimpleLogin account in the settings with your Proton account. If you have the Proton Unlimited, Business, or Visionary Plan, you will have SimpleLogin Premium for free.

Notable free features:

• 10 Shared Aliases
• Unlimited Replies
• 1 Recipient Mailbox

Self-Hosting Email

Advanced system administrators may consider setting up their own email server. Mail servers require attention and continuous maintenance in order to keep things secure and mail delivery reliable.

Combined software solutions

!!! recommendation

![Mailcow logo](assets/img/email/mailcow.svg){ align=right }

**Mailcow** is a more advanced mail server perfect for those with a bit more Linux experience. It has everything you need in a Docker container: A mail server with DKIM support, antivirus and spam monitoring, webmail and ActiveSync with SOGo, and web-based administration with 2FA support.

[:octicons-home-16: Homepage](https://mailcow.email){ .md-button .md-button--primary }
[:octicons-info-16:](https://mailcow.github.io/mailcow-dockerized-docs/){ .card-link title=Documentation}
[:octicons-code-16:](https://github.com/mailcow/mailcow-dockerized){ .card-link title="Source Code" }
[:octicons-heart-16:](https://www.servercow.de/mailcow?lang=en#sal){ .card-link title=Contribute }

!!! recommendation

![Mail-in-a-Box logo](assets/img/email/mail-in-a-box.svg){ align=right }

**Mail-in-a-Box** is an automated setup script for deploying a mail server on Ubuntu. Its goal is to make it easier for people to set up their own mail server.

[:octicons-home-16: Homepage](https://mailinabox.email){ .md-button .md-button--primary }
[:octicons-info-16:](https://mailinabox.email/guide.html){ .card-link title=Documentation}
[:octicons-code-16:](https://github.com/mail-in-a-box/mailinabox){ .card-link title="Source Code" }

For a more manual approach we've picked out these two articles:

• Setting up a mail server with OpenSMTPD, Dovecot and Rspamd (2019)
• How To Run Your Own Mail Server (August 2017)

Criteria

Please note we are not affiliated with any of the providers we recommend. In addition to our standard criteria, we have developed a clear set of requirements for any Email provider wishing to be recommended, including implementing industry best practices, modern technology and more. We suggest you familiarize yourself with this list before choosing an Email provider, and conduct your own research to ensure the Email provider you choose is the right choice for you.

技术

We regard these features as important in order to provide a safe and optimal service. You should consider whether the provider which has the features you require.

符合条件的最低要求。

• Encrypts email account data at rest with zero-access encryption.
• Export capability as Mbox or individual .eml with RFC5322 standard.
• Allow users to use their own domain name. Custom domain names are important to users because it allows them to maintain their agency from the service, should it turn bad or be acquired by another company which doesn't prioritize privacy.
• Operates on owned infrastructure, i.e. not built upon third-party email service providers.

Best Case:

• Encrypts all account data (Contacts, Calendars, etc) at rest with zero-access encryption.
• Integrated webmail E2EE/PGP encryption provided as a convenience.
• Support for WKD to allow improved discovery of public OpenPGP keys via HTTP. GnuPG users can get a key by typing: gpg --locate-key example_user@example.com
• Support for a temporary mailbox for external users. This is useful when you want to send an encrypted email, without sending an actual copy to your recipient. These emails usually have a limited lifespan and then are automatically deleted. They also don't require the recipient to configure any cryptography like OpenPGP.
• Availability of the email provider's services via an onion service.
• Subaddressing support.
• Catch-all or alias functionality for those who own their own domains.
• Use of standard email access protocols such as IMAP, SMTP or JMAP. Standard access protocols ensure customers can easily download all of their email, should they want to switch to another provider.

隐私

We prefer our recommended providers to collect as little data as possible.

符合条件的最低要求。

• Protect sender's IP address. Filter it from showing in the Received header field.
• Don't require personally identifiable information (PII) besides a username and a password.
• Privacy policy that meets the requirements defined by the GDPR
• Must not be hosted in the US due to ECPA which has yet to be reformed.

Best Case:

• Accepts anonymous payment options (cryptocurrency, cash, gift cards, etc.)

安全性

Email servers deal with a lot of very sensitive data. We expect that providers will adopt best industry practices in order to protect their members.

符合条件的最低要求。

• Protection of webmail with 2FA, such as TOTP.
• Zero access encryption, builds on encryption at rest. The provider does not have the decryption keys to the data they hold. This prevents a rogue employee leaking data they have access to or remote adversary from releasing data they have stolen by gaining unauthorized access to the server.
• DNSSEC support.
• No TLS errors or vulnerabilities when being profiled by tools such as Hardenize, testssl.sh, or Qualys SSL Labs; this includes certificate related errors and weak DH parameters, such as those that led to Logjam.
• A server suite preference (optional on TLSv1.3) for strong cipher suites which support forward secrecy and authenticated encryption.
• A valid MTA-STS and TLS-RPT policy.
• Valid DANE records.
• Valid SPF and DKIM records.
• Have a proper DMARC record and policy or use ARC for authentication. If DMARC authentication is being used, the policy must be set to reject or quarantine.
• A server suite preference of TLS 1.2 or later and a plan for RFC8996.
• SMTPS submission, assuming SMTP is used.
• Website security standards such as:
  • HTTP Strict Transport Security
  • Subresource Integrity if loading things from external domains.
• Must support viewing of Message headers, as it is a crucial forensic feature to determine if an email is a phishing attempt.

Best Case:

• Support for hardware authentication, i.e. U2F and WebAuthn. U2F and WebAuthn are more secure as they use a private key stored on a client-side hardware device to authenticate people, as opposed to a shared secret that is stored on the web server and on the client side when using TOTP. Furthermore, U2F and WebAuthn are more resistant to phishing as their authentication response is based on the authenticated domain name.
• DNS Certification Authority Authorization (CAA) Resource Record in addition to DANE support.
• Implementation of Authenticated Received Chain (ARC), this is useful for people who post to mailing lists RFC8617.
• Bug-bounty programs and/or a coordinated vulnerability-disclosure process.
• Website security standards such as:
  • Content Security Policy (CSP)
  • RFC9163 Expect-CT

Trust

You wouldn't trust your finances to someone with a fake identity, so why trust them with your email? We require our recommended providers to be public about their ownership or leadership. We also would like to see frequent transparency reports, especially in regard to how government requests are handled.

符合条件的最低要求。

• Public-facing leadership or ownership.

Best Case:

• Public-facing leadership.
• Frequent transparency reports.

Marketing

With the email providers we recommend we like to see responsible marketing.

符合条件的最低要求。

• Must self-host analytics (no Google Analytics, Adobe Analytics, etc). The provider's site must also comply with DNT (Do Not Track) for those who wish to opt-out.

Must not have any marketing which is irresponsible:

• Claims of "unbreakable encryption." Encryption should be used with the intention that it may not be secret in the future when the technology exists to crack it.

• Making guarantees of protecting anonymity 100%. When someone makes a claim that something is 100% it means there is no certainty for failure. We know people can quite easily deanonymize themselves in a number of ways, e.g.:

• Reusing personal information e.g. (email accounts, unique pseudonyms, etc) that they accessed without anonymity software (Tor, VPN, etc)

• Browser fingerprinting

Best Case:

• Clear and easy to read documentation. This includes things like, setting up 2FA, email clients, OpenPGP, etc.

Additional Functionality

While not strictly requirements, there are some other convenience or privacy factors we looked into when determining which providers to recommend.