In addition to (or instead of) an email provider recommended here, you may wish to consider a dedicated [email aliasing service](email-aliasing.md) to protect your privacy. Among other things, these services can help protect your real inbox from spam, prevent marketers from correlating your accounts, and encrypt all incoming messages with PGP.
- [More Information :material-arrow-right-drop-circle:](email-aliasing.md)
These providers natively support OpenPGP encryption/decryption and the [Web Key Directory standard](basics/email-security.md#what-is-the-web-key-directory-standard), allowing for provider-agnostic E2EE emails. 例えば、Proton MailのユーザはMailbox.orgのユーザにE2EEメッセージを送れますし、OpenPGPで暗号化された通知を、それをサポートするインターネットサービスから受け取ることができます。
When using E2EE technology like OpenPGP your email will still have some metadata that is not encrypted in the header of the email, generally including the subject line! Read more about [email metadata](basics/email-security.md#email-metadata-overview).
OpenPGP also does not support Forward secrecy, which means if either your or the recipient's private key is ever stolen, all previous messages encrypted with it will be exposed. [How do I protect my private keys?](basics/email-security.md#how-do-i-protect-my-private-keys)
**Proton Mail** は、プライバシー、暗号化、セキュリティ、使いやすさを重視したメールサービスです。 2013年から運営をされています。 Proton AGはスイスのジュネーブに拠点を置いています。 Accounts start with 1 GB of storage with their free plan.
Proton Mail has internal crash reports that are **not** shared with third parties. クラッシュレポートは次のように無効にできます: **設定** > **設定を開く** > **アカウント** > **セキュリティとプライバシー** > **クラッシュレポートを送信**
Proton Mailの有料会員は独自ドメインでサービスや [キャッチオール](https://proton.me/support/catch-all) アドレスを使うことができます。 Proton Mail also supports [sub-addressing](https://proton.me/support/creating-aliases), which is useful for people who don't want to purchase a domain.
Proton Mailはwebメールに [OpenPGP暗号化を組み込んでいます。](https://proton.me/support/how-to-use-pgp) 他のProton Mailアカウントへのメールは自動的に暗号化され、OpenPGPキーによる非Proton Mailアドレスへの暗号化はアカウント設定から簡単に有効化できます。 Proton also supports automatic external key discovery with [Web Key Directory (WKD)](https://wiki.gnupg.org/WKD). This means that emails sent to other providers which use WKD will be automatically encrypted with OpenPGP as well, without the need to manually exchange public PGP keys with your contacts. They also allow you to [encrypt messages to non-Proton Mail addresses without OpenPGP](https://proton.me/support/password-protected-emails), without the need for them to sign up for a Proton Mail account.
Proton Mail also publishes the public keys of Proton accounts via HTTP from their WKD. これにより、Proton Mailを使っていない人でも、Proton MailアカウントのOpenPGPキーを簡単に見つけることができ、プロバイダをまたいだE2EEが可能になります。 This only applies to email addresses ending in one of Proton's own domains, like @proton.me. If you use a custom domain, you must [configure WKD](./basics/email-security.md#what-is-the-web-key-directory-standard) separately.
有料アカウントを持っており、しかし14日を過ぎても [請求への支払いが無い](https://proton.me/support/delinquency) 場合、データにアクセスできなくなります。 30日を過ぎるとアカウントは滞納者となり、受信メールは届かなくなります。 この期間も請求は継続されます。 Proton will [delete inactive free accounts](https://proton.me/support/inactive-accounts) after one year. You **cannot** reuse the email address on a deactivated account.
Mailbox.org lets you use your own domain, and they support [catch-all](https://kb.mailbox.org/en/private/custom-domains/how-to-set-up-a-catch-all-alias-with-a-custom-domain-name) addresses. Mailbox.org also supports [sub-addressing](https://kb.mailbox.org/en/private/account-article/what-is-an-alias-and-how-do-i-use-it), which is useful if you don't want to purchase a domain.
Mailbox.orgは決済プロセッサBitPayがドイツでの業務を停止したために暗号通貨を受け付けていません。 However, they do accept cash by mail, cash payment to bank account, bank transfer, credit card, PayPal and couple of German-specific processors: paydirekt and Sofortüberweisung.
Mailbox.org supports [two factor authentication](https://kb.mailbox.org/en/private/account-article/how-to-use-two-factor-authentication-2fa) for their webmail only. You can use either TOTP or a [YubiKey](https://en.wikipedia.org/wiki/YubiKey) via the [YubiCloud](https://yubico.com/products/services-software/yubicloud). [WebAuthn](https://en.wikipedia.org/wiki/WebAuthn) などのウェブ標準はまだサポートされていません。
Mailbox.org allows for encryption of incoming mail using their [encrypted mailbox](https://kb.mailbox.org/en/private/e-mail-article/your-encrypted-mailbox). 新しいメッセージを受信するとすぐにあなたの公開鍵で暗号化されます。
However, [Open-Exchange](https://en.wikipedia.org/wiki/Open-Xchange), the software platform used by Mailbox.org, [does not support](https://kb.mailbox.org/en/private/security-privacy-article/encryption-of-calendar-and-address-book) the encryption of your address book and calendar. その情報については、 [スタンドアロンオプション](calendar.md) の方が適切であるかもしれません。
Mailbox.org has [integrated encryption](https://kb.mailbox.org/en/private/e-mail-article/send-encrypted-e-mails-with-guard) in their webmail, which simplifies sending messages to people with public OpenPGP keys. They also allow [remote recipients to decrypt an email](https://kb.mailbox.org/en/private/e-mail-article/my-recipient-does-not-use-pgp) on Mailbox.org's servers. この機能はリモートの受信者がOpenPGPを持っておらず、自分のメールボックスにあるメールのコピーを複合できない場合に便利です。
Mailbox.orgは [Web Key Directory (WKD)](https://wiki.gnupg.org/WKD) からHTTP経由で公開鍵を発見することもサポートしています。 これにより、Mailbox.orgを使っていない人でも、Mailbox.orgアカウントのOpenPGPキーを簡単に見つけることができ、プロバイダをまたいだE2EEが可能になります。 This only applies to email addresses ending in one of Mailbox.org's own domains, like @mailbox.org. If you use a custom domain, you must [configure WKD](./basics/email-security.md#what-is-the-web-key-directory-standard) separately.
Your account will be set to a restricted user account when your contract ends. It will be irrevocably deleted after [30 days](https://kb.mailbox.org/en/private/payment-article/what-happens-at-the-end-of-my-contract).
You can access your Mailbox.org account via IMAP/SMTP using their [.onion service](https://kb.mailbox.org/en/private/faq-article/the-tor-exit-node-of-mailbox-org). ただし .onionサービスからwebメールのインターフェイスにアクセスすることはできず、TLS証明書のエラーが発生する可能性があります。
All accounts come with limited cloud storage that [can be encrypted](https://kb.mailbox.org/en/private/drive-article/encrypt-files-on-your-drive). Mailbox.org also offers the alias [@secure.mailbox.org](https://kb.mailbox.org/en/private/e-mail-article/ensuring-e-mails-are-sent-securely), which enforces the TLS encryption on the connection between mail servers, otherwise the message will not be sent at all. Mailbox.orgはIMAPやPOP3のような標準的なアクセスプロトコルに加え、 [Exchange ActiveSync](https://en.wikipedia.org/wiki/Exchange_ActiveSync) もサポートしています。
**Tuta** is an email service with a focus on security and privacy through the use of encryption. Tuta has been in operation since **2011** and is based in Hanover, Germany. Accounts start with 1GB storage with their free plan.
Tuta doesn't support the [IMAP protocol](https://tuta.com/faq/#imap) or the use of third-party [email clients](email-clients.md), and you also won't be able to add [external email accounts](https://github.com/tutao/tutanota/issues/544#issuecomment-670473647) to the Tuta app. [Email import](https://github.com/tutao/tutanota/issues/630) is not currently supported either, though this is [due to be changed](https://tuta.com/blog/posts/kickoff-import). Emails can be exported [individually or by bulk selection](https://tuta.com/support#generalMail) per folder, which may be inconvenient if you have many folders.
Paid Tuta accounts can use either 15 or 30 aliases depending on their plan and unlimited aliases on [custom domains](https://tuta.com/support#custom-domain). Tuta doesn't allow for [sub-addressing (plus addresses)](https://tuta.com/support#plus), but you can use a [catch-all](https://tuta.com/support#settings-global) with a custom domain.
Tuta only directly accepts credit cards and PayPal, however [cryptocurrency](cryptocurrency.md) can be used to purchase gift cards via their [partnership](https://tuta.com/faq/#cryptocurrency) with Proxystore.
Tuta has [zero access encryption at rest](https://tuta.com/support#what-encrypted) for your emails, [address book contacts](https://tuta.com/support#encrypted-address-book), and [calendars](https://tuta.com/support#calendar). This means the messages and other data stored in your account are only readable by you.
Tutaは[OpenPGPを使用していません](https://tuta.com/support/#pgp)。 Tuta accounts can only receive encrypted emails from non-Tuta email accounts when sent via a [temporary Tuta mailbox](https://tuta.com/support/#encrypted-email-external).
Tuta offers the business version of [Tuta to non-profit organizations](https://tuta.com/blog/posts/secure-email-for-non-profit) for free or with a heavy discount.
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.
**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.
**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.
- [Setting up a mail server with OpenSMTPD, Dovecot and Rspamd](https://poolp.org/posts/2019-09-14/setting-up-a-mail-server-with-opensmtpd-dovecot-and-rspamd) (2019)
- [How To Run Your Own Mail Server](https://c0ffee.net/blog/mail-server-guide) (August 2017)
**Please note we are not affiliated with any of the providers we recommend.** In addition to [our standard criteria](about/criteria.md), 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.
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.
- Export capability as [Mbox](https://en.wikipedia.org/wiki/Mbox) or individual .eml with [RFC5322](https://datatracker.ietf.org/doc/rfc5322) standard.
- Allow users to use their own [domain name](https://en.wikipedia.org/wiki/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.
- 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](https://wiki.gnupg.org/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](https://en.wikipedia.org/wiki/.onion).
- Catch-all or alias functionality for those who own their own domains.
- Use of standard email access protocols such as IMAP, SMTP or [JMAP](https://en.wikipedia.org/wiki/JSON_Meta_Application_Protocol). Standard access protocols ensure customers can easily download all of their email, should they want to switch to another provider.
- 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.
- No TLS errors or vulnerabilities when being profiled by tools such as [Hardenize](https://hardenize.com), [testssl.sh](https://testssl.sh), or [Qualys SSL Labs](https://ssllabs.com/ssltest); this includes certificate related errors and weak DH parameters, such as those that led to [Logjam](https://en.wikipedia.org/wiki/Logjam_(computer_security)).
- Have a proper [DMARC](https://en.wikipedia.org/wiki/DMARC) record and policy or use [ARC](https://en.wikipedia.org/wiki/Authenticated_Received_Chain) for authentication. If DMARC authentication is being used, the policy must be set to `reject` or `quarantine`.
- [HTTP Strict Transport Security](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security)
- [Subresource Integrity](https://en.wikipedia.org/wiki/Subresource_Integrity) if loading things from external domains.
- Must support viewing of [Message headers](https://en.wikipedia.org/wiki/Email#Message_header), as it is a crucial forensic feature to determine if an email is a phishing attempt.
- ハードウェア認証のサポート、つまり U2Fと[WebAuthn](https://en.wikipedia.org/wiki/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](https://en.wikipedia.org/wiki/Domain_name).
- [DNS Certification Authority Authorization (CAA) Resource Record](https://tools.ietf.org/html/rfc6844) in addition to DANE support.
- Implementation of [Authenticated Received Chain (ARC)](https://en.wikipedia.org/wiki/Authenticated_Received_Chain), this is useful for people who post to mailing lists [RFC8617](https://tools.ietf.org/html/rfc8617).
