Attachment and email size limits

You can attach multiple files to an email in your ProtonMail account in two ways: through the Attachment feature and through the File directory

Attaching files through the Attachment feature

1. Open your email composer by selecting New message in the left sidebar.

New message

2. Click on the Attachment button at the bottom left.

3. Select the first file you would like to attach. Press and hold the Ctrl / Cmd button while selecting the other documents you would like to attach. 

Attaching files through the File directory

1. Open your email composer by selecting New message in the left sidebar.

New message

2. Drag and drop the file you would like to attach from your desktop directly into the email composer. Your file should upload automatically. 

The total size limit of your attachments is 25 MB per email and the total number of files you can attach is 100. These limits apply to both incoming and outgoing emails and to all ProtonMail plans.

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  1. Matthew Tooch

    Is there any plans on enlarging the send and receive attachment size? For instance Tutamail can send and receive 25 mb attachments. I’m considering switching because of the larger files size available, but prefer Protonmail

  2. ProtonMail Support

    The attachment size has been increased to 25 MB.

  3. DM

    Why is it with the ios app the only attachment option is photos? There should be a way to add basic office docs.

  4. ProtonMail Support

    The option to import another files is now available on our iOS app.

  5. Net

    Any plans to increase the size of attachments in the future, especially for direct transfer of emails inside protonmail?

  6. ProtonMail Support

    We have increased the attachment limit to 25MB.

  7. Surfer

    Will there be a way on the mobile app to send attachments other than just pictures? It would be very useful to be able to access Google Drive, Dropbox, etc. and add files from these sources to a Proton mail message (from mobile).


  8. Mariluz

    How can I increase the font size?

  9. ProtonMail Support

    To increase the font size in the composer, click on Text options (the button with the letter A) to expand the additional text options toolbar.

  10. Enrico

    Can I send .zip files in the attachement?

  11. Proton Editor

    Yes, you can attach ZIP files to an email message, just make sure the total size of the attachments is under the 25 MB limit.

  12. Tarek

    We need to increase the attachment limit please

  13. rudzik

    How can I remove and suppress a file to an email received (for example to decrease my data space) ?

  14. ProtonMail Support

    You cannot remove just an attachment from a received message. If you need to free up storage space, you will need to delete the whole message.

  15. bulk up

    25MB attachment is amateur. If I am using PROTON it’s because I don’t want to upload to YouTube or any other big brother machine. Let’s get it up’d or create a space where we can load it to. Thanks – keep up the good work!

  16. Monier

    Attachments of only a few MB seem to be crashing Firefox/Chrome and causes Edge to hang… any fixes coming soon?

  17. ProtonMail Support

    Can you please contact our support team using the support form:, at or so we can look into this further?

  18. Tejido de Esparto

    I can’t download any of te attachments that i recieve. Any ideas why?

  19. ProtonMail Support

    Please contact our support team at

  20. Channing Elizabeth Johnston

    My protonmail. Which was [redacted]@protonmail. Was hacked over a month ago by unknown hackers. They used this account and 2 gmail accounts to send out images of cjildren, violent joke memes and links to. Kiddie porn. One lady took over my identity and hacked into my LinkedIn account, sending out adds and networking as me. Also, she joined meet up dotcom as a writer last NAME corrosion formed a writer’s anonymous group under my email name and opened a PayPal account and hacked. Twitter and FB.. I need to get back into my protonmail if pissible.

  21. ProtonMail Support

    Please contact our support team at for assistance.

  22. Emmet Arries

    Is there any plan to increase the Attachment limit? I need to send attachments bigger than 25mb. Thank you!

  23. ProtonMail Support

    There are no plans to increase the attachment limit at this time, but we may consider this in the future.

  24. Jean-Pierre Bélanger

    I have geen using the proton to transfer my emails from yahoo to protonmail using thunderbird.

    Quite often, it complains about security timeout but I noticed that it was a side effect of large emails; it refused to transfer files where attachment is too big (mostly pictures). That error kept bugging me to manualy select a new block of email and resend it manually. What a pain!

    Yahoo has a limit of 25 MB, just as Protonmail. However, my theory is that Protonmail has a limit of 25 MB for attachment AFTER being encrypted. One of your FAQ tells that the compression ratio is about 1.4 times the non-encrypted size. I think that you should increase your maximum size of stored emails to 35 MB and accept receiving non-encrypted messages of 25 MB. That would keep protonmail works fine with other people who use yahoo email domains (and others)

  25. Anthony

    Just to be sure I understand limit per email is 25mb, how many docs attached? 100 files per email?

    Is there another limit on the number of emails with attachments in total?

  26. ProtonMail Support

    The size limit per message is a little less than 25 MB for the whole message before encryption, including the message body and attachments. The number of attachments allowed in one message is 100.

  27. Anonymous

    Can administrators at ProtonMail server see the contents of attachments, if they are uploaded via ProtonMail?

    I understand external email arrives as plaintext unless sender also uses ProtonMail or encrypts with PGP, however, if we use ProtonMail interface or app, are attachments encrypted before uploading?

  28. ProtonMail Support

    All mail content is encrypted locally before the message is sent. ProtonMail does not have access to any of the stored email content.

  29. Sara

    i need to send and receive large documents for proof-reading. 25mb is a problem for me there. will there be an option to upgrade not only the storage for paid users but also for attachements?

  30. ProtonMail Support

    At the moment, no. Most email services only support attachments up to 25 MB or even 20 MB.

  31. Cynthia

    Only being able to send attachments from photos or google drive on iOS. The purpose of a secure email system is to move away from nonsecure platforms such as google drive. Severe limitation.

  32. ProtonMail Support

    You can add attachments from the apps installed on your device. If you don’t have Google Drive installed/set up on your device, it will not show up when adding attachments.

  33. Tomm

    I would appreciate if there where more limits for attachments for beginning it could be only in paid account, like 50MB or 100MB or even in some attached link to safe drive you are working on.

  34. ProtonMail Support

    Most email services will reject messages larger than 25 MB, so this may not be a viable feature.

  35. Pauline Bradshaw

    How can I attach old emails to a new email. Can I do this?

  36. ProtonMail Support

    You can use the Export option to save the email and then attach the file to a new message.

  37. guido

    Are the Attached file encrypted with proton mail?

  38. ProtonMail Support
  39. Anonymous

    Not being able to receive an email of more than 25mb is a joke for a paid account.

  40. ProtonMail Support

    Message size limit of 25 MB is standard for most email services. We’ll see if this can be improved in the future.

  41. Brian McLean

    When I add an attachment to an email, I like to open it from the draft email before sending it so that I can confirm that I have actually attached the correct attachment. This has saved me more times than I would like to admit from sending the wrong attachment.

    This works well in, but I can’t see a way to make this happen with protonmail. I have gone through the settings, but I can’t see one to have attachments open. What I get when I try to open an attachment to and unsent email, is an option to save the attachment, which I do not need. This is not so bad with attachments to emails I receive as I usually want to save them anyway, but it would be nice for that as well to have them open directly.

  42. ProtonMail Support

    Hi, ProtonMail apps don’t have a preview option for attachments, which is why the download is required. We’ll try to improve this in the future.

  43. Anonymous

    i am an architect/builder…..i got protonmail to protect/separate my business communications (and can justify the expense that way) but the 25MB attachment limit is a joke! i cant even send a zipped file with a few pdfs in it!!!

  44. ProtonMail Support

    Hi, while the 25MB message size limit is fairly standard for most email providers, we’ll see if this can be improved in the future.

  45. Michael

    Can I send emails to others without an expiration date? Does this depend on whether it is encrypted or not if this is even an option?

  46. ProtonMail Support

    Yes, you can send emails without expiration. Messages sent with a password (encrypted for outside) will always have expiration time added.
    If the recipient uses PGP, you can send end-to-end encrypted messages without expiration time.

  47. Keith Shedron

    Greetings: I cannot find how to embed links into an email response. I can embed links into a message that I originate but I do not have a bar with the link icon when responding to a message. Am I missing something?

  48. ProtonMail Support

    If you’re replying to a plaintext email, the plaintext composer is loaded automatically. You can switch to the Normal (HTML) composer to be able to add links.

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