Great answers

…to all your questions. Please also check our How-to to learn everything you need to know about Tutanota.

Table of contents

一般的な質問

Tutanotaは無料で利用できますか?

はい、Tutanota ウェブメールクライアントは、個人ユーザー向けの 1 GB のストレージ容量が永遠に無料で利用
できます。

「Tutanota」という名前の由来はなんですか?

Tutanota is derived from Latin and contains the words "tuta" and "nota" which means "secure message".

Tutanotaはオープンソースですか。

Yes, all Tutanota clients are published as open source under GPLv3. Check out our GitHub repository. We welcome you to review the code, to give us feedback or to contribute!

Tutanotaは認証されていますか?

2013 年 11 月、TutanotaはSySS GmbH によって広範な侵入テストを受けました。 テスト中に専門家はシステムにアクセスしたり、機密データを取得することができませんでした。

ビジネス用にTutanotaを使用することはできますか?

Yes, Tutanota offers a whitelabel version for businesses, which includes customizations of the logo and design. You can also place the login for your employees directly on a subdomain of your website.

Learn here how to whitelabel Tutanota for your business.

自分のアカウントにアクセスできません。どうすればいいのでしょうか?
password lost login

If you can't access your account, this has been caused by one of the following reasons:

  • You forgot your password or lost your second factor: Please read the howto entry on How do I reset my password or second factor?.
  • Your account got suspended due to unpaid invoices: Your account may be suspended if you don't pay your open bills for a long time. Just contact us if you want to continue using your account and include the email address of your suspended Tutanota account.
  • Your account was disabled due to another reason: Some accounts get disabled due to a violation of our Terms of Service. You can contact us if you think that we made a mistake. Please include the email address of your suspended Tutanota account.

Tutanota パスワード

Tutanota secures my private key with my password. Can you access my password?
recovery reset password

No. When a password is used for authentication (login), it is not necessary that it is known to the server you want to authenticate with. The server only needs a fingerprint (hash) of your password. With Tutanota your hash for authentication is calculated by your browser and only the hash is being sent. Your password never travels the Internet in plain text and it is never seen by our server. As hashes are non-invertible, the server is unable to reconstruct your password from the hash. The server is not able to decrypt your message, but still able to log you in.

Recommended for further reading: Learn how Tutanota automates the encryption process while leaving you in full control of your encrypted data.

パスワードにはどのようなハッシュ関数が使用されていますか?

Your password is salted and hashed with Bcrypt on your device before being transmitted to Tutanota. Bcrypt is the most reliable method because brute-force attacks need much more time in comparison to conventional methods such as MD5 or SHA. With this method we guarantee an integrated confidentiality and we allow you to access and decrypt your emails from desktops and mobile devices instantly.

How do I choose a strong password?

Tutanota uses a password strength indicator that takes several aspects of a password into consideration to make it secure. You can find additional tips on how to choose a strong password here.

Tutanota has no limitations in regard to the password length or used characters; all unicode characters are respected.

Tutanotaは二段階認証(2FA)をサポートしていますか?

はい。TutanotaはU2FまたはTOTPの二段階認証をサポートしています。こちらで詳細な設定方法を確認できます

U2Fは現在Firefoxでは動作しないことに注意してください。

セキュリティーとプライバシー

Where does the encryption process take place?

データの暗号化と復号化は、ログイン時に常にデバイス上でローカルに行われます。すべてのデータにはエンドツーエンドの暗号化がなされており、パスワードを持つあなただけがデータにアクセスすることができます。

What is encrypted and what can you read?
暗号化

すべてのデータ(連絡先、メール)を暗号化します。件名、内容、添付ファイルも暗号化します。

わたしたちは次のものだけを読むことができます(メタデータ):

送信者 受信者
*メールの日付

将来的には、メタデータも非表示にする可能性を検討しています。

私の鍵はどこで生成され、秘密鍵はどのように保護されるでしょうか?

Your private and your public keys are generated locally within your browser upon registration. Your private key is encrypted with your password. This way your login password receives the status of the private key. The key is encrypted so strong that only you can use the key for encrypting and decrypting data. This is why a strong password is essential. An automatic password check on the client makes sure that you use a strong password. Your password is never transmitted to the server in plain text. It is salted and then hashed with bcrypt locally on your device so that neither the server nor we have access to your password. With this innovative design you can access your encrypted inbox from any device (desktop, mobile) easily.

Tutanotaはどんな暗号化アルゴリズムを使用していますか?

For the email encryption between users, Tutanota uses a standardized, hybrid method consisting of a symmetrical and an asymmetrical algorithm. Tutanota uses AES with a length of 128 bit and RSA with 2048 bit. Emails to external recipients are encrypted symmetrically with AES 128 bit.

Tutanota で私のメールはどのように暗号化されるのでしょうか。

The system automatically encrypts all emails stored in Tutanota. Emails between Tutanota users are automatically encrypted end-to-end, emails to external users can be secured with the help of a password. Here we explain the differences between a confidential (end-to-end encrypted) and a non-confidential email.

Independent of the end-to-end encryption, the transport between client and Tutanota servers is secured with SSL and DANE to maximize security.

Where are the Tutanota servers located?

Tutanotaのサーバーは安全なドイツのデータセンターにあります。保存された全てのデータはドイツの強固なプライバシー保護法に則り管理されます。またこのこととは別に、これらのデータは全て端末相互の間で暗号化され、プロバイダーのTutao GmbH はおろかどのサードパーティーにも、データを読むことはできません。

Does Tutanota log IP addresses or can I use my encrypted mailbox anonymously?

私たちはあなたがログインしたときやメールを送るときにIPアドレスを記録しません。また、あなたの居場所が特定されないよう送受信されたメールのIPアドレスも削除されます。

Tutanotaが匿名メールサービスを提供する方法については、私たちのブログをご覧ください。登録に際しては、電話番号などの個人情報を提供する必要はありません。また、ビットコインでPremiumやProなどの有料プランの料金を支払うことができます。

Is my address book within Tutanota encrypted?

Yes, all data within Tutanota is end-to-end encrypted and only accessible with your password. Scanning and profiling of your data is not possible.

ログの収集について:Tutanotaは何についてのログを収集し、それをどれぐらいの期間保存しますか?

エラーが発生した場合、Tutanota クライアントはエラーメッセージを表示し、エラーの詳細をサポートに送信する機能を提供します。これらのエラーの詳細には、個人データは含まれず、クライアントで発生したエラーを追跡するためのサポートによって使用されます。

また、サーバー側で技術的な情報、警告、およびエラーメッセージを記録します。これらのメッセージには、個人データが含まれることはなく、Tutanota の改善にも使用されます。これらのログは14日間保持されます。

遠隔でセッションを無効にすることができますか?
ip address log logging security

Yes. You can view and remotely close active sessions under Settings -> Login.

Check our How-to to learn how to enable storing of closed sessions to monitor whether someone else has access to your account. To guarantee the users' privacy, we have implemented the feature as follows:

  • The IP address is stored encrypted, and only the user can decrypt this information. No one else - not even we at Tutanota - can access this information.
  • IP addresses are only stored for one week and then automatically deleted.
Do you delete inactive accounts / recycle email addresses?

Free of charge accounts are deleted if they were not used for at least six months. Your deleted email address (also if it is an alias) will not be recycled for security reasons. There must be no possibility that someone else is able to register your previously used email address, and then, by accident, receive a confidential email that was meant for you.

アプリ、クライアント、手順

Tutanotaの使い方
How to How-to settings instructions help support

Tutanotaは、簡単に利用できます。当初から私たちはユーザビリティに焦点を当て、バック グラウンドでの暗号化プロセスを維持してきました。何かをインストールしたり、鍵の処理を心配したりする必要はありません。Tutanotaは、Gmailやその他のウェブメールサービスと同等のユーザビリティを提供しています。

Tutanotaはすぐに使い始められます。何か質問がある場合は、下記の詳しい使い方 を確認してください。

ここではTutanotaのすべての設定について説明しています。ユーザビリティについての以下のような質問にも答えています。

暗号化されたメールを送信する方法
非機密設定に切り替える方法
連絡先の並べ替え方法
フォルダーの追加/名前の変更/削除の方法
Premiumにアップグレードする方法
別名(エイリアス)を設定する方法
エイリアスからメールを送信する方法
Premiumユーザーのパスワードを管理する方法
自分のドメインでメールを送信する方法
暗号化された問い合わせフォームを自分のウェブサイトに追加する方法

どこでTutanota のアプリを入手できますか?

以下のストアから Tutanota アプリをダウンロードできます。

Android 用 APK を直接ダウンロードして、インストールすることもできます。アプリストアを使用するかわりに手動でアプリをインストールした場合、自動的には更新されないことに留意してください。アップデートの通知を受け取るためには、このリンクを使用して RSS リーダーに私たちのブログを追加してください : {rssFeedLink}

Androidのプッシュ通知が遅れて届きますが、どうすればいいのでしょうか?

携帯電話でアプリの設定を確認してください。TutanotaはGoogleのプッシュ通知サービスを使用していないため、プッシュ通知を即座に受信するには、バッテリーの最適化を無効にする必要があります。

どこでTutanota のデスクトップ用クライアントを入手できますか?
Is it possible to merge several Tutanota email addresses in one account?

Yes, you can add existing email addresses (e.g. Alice2, Alice3) as aliases to a Premium account (Alice1). Before you can add the aliases, you need to delete the other accounts (Alice2, Alice3) and specify the Premium account (Alice1) as the take over account upon deletion. We explain here how to take over the email addresses.

Please note: You are only transferring the email addresses. Emails and contacts stored in the deleted accounts (Alice2, Alice3) are being deleted. Please export important emails before deleting the accounts.

Tutanota にダークテーマはありますか?

Yes. Before logging in, click on 'More' and 'Switch color theme' to switch to the dark theme. This works in all Tutanota clients (web, desktop, apps).

Why does Tutanota not use pgp?

Current encryption standards like pgp and S/MIME have several issue that we plan to address with Tutanota. These standards do not support forward secrecy and are not resistant to attacks from quantum computers.

In addition, it is important to us that the subject line in emails is also encrypted. That's why we have developed a solution that is also based on recognized algorithms (RSA and AES) and that automatically encrypts the subject, the content and the attachments. In the future, we plan to upgrade these algorithms to quantum-resistant ones that also support forward secrecy. You can find more information on Tutanota's encryption design on our blog.

We also see the importance that Tutanota needs to be interoperable with other encryption solutions. We will develop an API so that Tutanota users can communicate with users of other secure services confidentially in the future.

What browsers does Tutanota support? Via what browsers can external recipients check their encrypted emails?

Tutanota supports the current version of the following browsers:

  • Firefox (desktop)
  • Opera (desktop, Android)
  • Chrome (desktop, Android)
  • Safari from version 11.0 (desktop, iOS)
  • Microsoft Edge (desktop)

    Tutanota also works in Internet Explorer 11, but this browser is not officially supported.

開発が進められています。次にどうなるのでしょうか。
ロードマップ

こちらこちら をご覧ください。

What is the maximum size for emails and attachments?

Tutanota経由で送信された添付ファイルを含むメールのサイズは、現時点では25 MBに制限されています。

私のTutanotaメールをIMAP経由で別のメールクライアントに取り込むことはできますか?
gmail、outlook、yahoo、thunderbird、リダイレクト

This is not possible as we could not guarantee end-to-end encryption for your data. Instead Tutanota offers email desktop clients for Linux, Mac OS and Windows.

外部の受信者として、後で自分のメールに再アクセスできますか。

Yes, you can always access the emails sent via Tutanota through the link from your latest notification email. Old notification links from the same sender are de-activated for security reasons. Your exchanged password, however, stays unchanged as long as the sender does not change it. If you have saved the password upon accessing your confidential emails in your browser, you do not have to re-enter it.

Are emails to other Tutanota users always encrypted?

Yes, when sending emails from Tutanota to Tutanota, all emails are encrypted automatically end-to-end on your device. You do not have to enter any passwords.

Can Tutanota encrypt emails to other email services (external recipients)?

Yes. Tutanota uses a preshared password for sending an encrypted message to an external recipient, to someone who does not use Tutanota. Please check our how-to to learn how to send encrypted emails to external recipients.

Tutanotaにエイリアスのメールアドレスを追加することはできますか?

Email aliases are additional email addresses that you can use with the same mailbox without having to switch accounts. Aliases are a Premium feature. If you upgrade to Premium (€1 per month), you can add up to 5 aliases.

Find out how to add aliases in our How-to.

Tutanotaでカスタムドメイン(自身のドメイン)を利用できますか?

はい。Tutanota Premiumと Pro はカスタムドメインをサポートしています。アップグレード後に、必要な数のドメインを追加できます。Tutanota アカウントに独自のドメインを追加する方法については、こちらをご覧ください

Does Tutanota use a spam filter?
false spam block legit newsletter

Yes, Tutanota uses a spam filter to keep your mailbox free from spam. We are improving this filter continuously. Should you receive spam emails in your inbox, you can also configure your own spam rules here.

In paid accounts, only admins can create spam rules that are being applied across all users.

Are there email limits to protect Tutanota from being abused by spammers?

Yes, Tutanota uses different variables to calculate email limits for individual accounts. This is necessary to protect our free and anonymous email service from spammers who try to abuse Tutanota. If spammers were able to abuse Tutanota, it would harm all Tutanota users - ie Tutanota domains could end up on email blacklists, which we have to prevent under all circumstances.

If you receive the following message in your Tutanota account "It looks like you exceeded the number of allowed emails. Please try again later.", the anti-spam protection method has stopped your account temporarily from sending new emails. Please wait a day or two to send new emails again.

If you need to send more emails immediately, please upgrade to our affordable Premium version (1 Euro per month) as limits for Premium users are much higher. Simply click on 'Premium' in your top menu bar of Tutanota.

Please note that Tutanota is not meant for sending out mass mailings such as newsletters. Please read our Terms & Conditions for details

その他

If I upgrade to Premium, can I downgrade to free again?
Premium Free subscribe unsubscribe

Yes, you can downgrade back to free anytime. Before this, you need to disable all extra bookings (aliases, storage, additional users). You can keep your main Tutanota email address as a free account.

Check here how you can upgrade and downgrade.

My newly created account has been put on hold for 48 hours. What should I do?

Some accounts are automatically marked for approval to prevent abuse and to enable you to sign up for a 100% anonymous email service.

During these 48 hours emails cannot be sent or received. Please do not share your new email address before the blocking has been lifted.

I have received an abusive email (spam, phishing) from one of your domains. How do I report abuse?
fraud stalker threat abuse abusive phishing

If you would like to inform us about abusive usage of one of our domains (tutanota.com, tutanota.de, tutamail.com, tuta.io, keemail.me), please contact us at abuse@tutao.de. Please forward the abusive message to us if appropiate.

If you would like to report abusive usage originating from another provider's email address, you can find contact addresses at abuse.net.

非営利団体のための特別オファー
無料で

For non-profit organizations (NPOs) we have the following special offers:

  1. If you are located in Austria, Canada, France, Germany, Italy, Netherlands, or in Switzerland you can get Tutanota Premium as a donation in cooperation with our partners Stifter-helfen and tech-soup. Please find details on how non-profits can get Tutanota for free on our blog.
  2. Coming soon: If you are located in Poland, you can get Tutanota Premium as a donation in cooperation with our partner tech-soup.
  3. For all other countries we offer a discount of 50%. Get in touch with us directly.

Conditions:

  • If you make use of Tutanota Premium as a donation, our partners collects a small administration fee to cover their expenses for offering the software donations.
  • The free or discounted Tutanota Premium offer is limited to users. Additional upgrades, e.g. storage packages, have to be paid at the standard price.
  • Only up to 50 users are included in the donation. If you need more users, you cannot apply for the donations above. But of course you will get the 50% discount offered by us. Simply get in touch with us directly.