Encrypting attachments

Attachments are automatically encrypted and decrypted within your ProtonMail inbox, just as your messages are. You don’t need to do anything further to ensure they are encrypted.

Attachments (including those sent to or received from non-Protonmail email accounts) are stored encrypted on our servers and cannot be decrypted by anyone except you, by using the correct mailbox password

Attachments sent to a ProtonMail account from a non-ProtonMail account may still exist unencrypted within the sender’s Sent folder, however. The safest way to protect your attachments is to make sure the person you are communicating with also has a ProtonMail account. (You can sign up for one here; it’s free.)

Download encrypted attachments

When you receive a message with an attachment, the name of the attachment appears at the bottom of the email. You can decrypt stored attachments immediately within your browser by clicking the download icon, which will save the attachment to your device.

To download all attachments at once, click Download all. This will download all the attachments in a .zip file, which you can extract on your device to access the unencrypted files.

This will bring up the encrypted attachment as an in-browser preview, rather than download the file to your device.

You can use the arrow buttons at the top of the preview to scroll through all the files in that email, or click the download icon to download the image you are currently viewing. Click the cross in the top-right corner to close the preview pane.

Encrypt attachments for non-ProtonMail users

The Encrypt for Outside Users feature also supports end-to-end encryption of attachments. Attachments sent within an end-to-end encrypted message are saved in the password protected link of the encrypted message.

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  1. Steve Gregg

    What I do is encrypt the file (using PGP) before attaching it. The only drawback is exchanging keys with the other person. I eagerly await the encryption feature, though.

  2. Simon

    +1 Vote!

  3. Anon

    +1000 Votes

  4. David Apple

    +1 vote. Please make this priority one. I’m reluctant to switch from Gmail without this feature.

  5. Shallcross

    This would definitely help bring protonmail on par with other encrypted email providers, and then let its real quality shine out above the others.

  6. Idea Exchanger

    Thanks to the internet, email is moving away from mainly text-based communications. And as we move from the general Information Age into the individual Knowledge Age, it becomes necessary for us to learn how to transform information into useful skills. An efficient and effective tool for this purpose is interactive-multimedia. I see an email program with these capabilities, as a good way to send out interactive simulations to many, and send subsequent the exercise based on the individual’s response. And, security and privacy are a prime requirement for media, as well as text. I look forward to seeing the launch features!

  7. Daniele

    What happens if I send an email with attachment to multiple recipients?
    I mean, the encryption is end-to-end, so if all the recipients are ProtonMail account, then I think that my browser must encrypt the attachment multiple times, one per recipient, and send multiple email, one per recipient.
    Am I correct?

  8. Lunar

    How large can attachments be? Attachments I’ve sent , can be opened by receiver without password?

  9. ProtonMail Support

    You can read about the attachments limit here https://protonmail.com/support/knowledge-base/attaching-multiple-documents-to-a-message/. For more details you can contact us on contact@protonmail.ch or via the Report Bug button

  10. julian

    I cannot decrypt the attachments using my mac’s safari browser. The message reads: “your browser lacks features to download encrypted attachments directly…” Are there settings I can adjust so attached files sent from another proton user opens immediately so I can save the document in its unencrypted form

  11. ProtonMail Support

    This process of encrypted attachments requires the latest browser technology. The latest versions of both Chrome and Firefox support this technology flawlessly; however, Safari does not. At this time, most safari users can right click on the attachment and save the attachment. The file name will not be saved and will show up in your downloaded files at “unknown”. Some attachments may have their extensions removed using Safari. We are working on making this process as seamless as possible; and, as always, we recommend you try a different browser if you are having trouble.

  12. Schikker

    Please be informed, that downloading attachment in safari by right-click isn’t working at all because the context menu doesn’t offer to download the attachment. Only workaround as it seems is to switch browser in such cases… I’ll be patient and wait for next version ;-)

  13. bob

    I sent an email from yahoo, to my free protonmail account. I was able to download the attachment without a password. Am I missing something?

  14. ProtonMail Support

    This feature is for sending emails from ProtonMail to non-ProtonMail accounts. Can you please contact us at contact@protonmail.com or use the Report Bug button so we can assist you?

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