Encrypt Message for Non-ProtonMail Recipients

Messages between ProtonMail users are automatically end-to-end encrypted (E2EE), and it is possible to send a non-ProtonMail user a message that is end-to-end encrypted using PGP.

In addition to this, we offer an Encrypt Message for Non-ProtonMail users feature that allows you to send E2EE messages to any email user without the need for PGP. The recipient receives an email telling them that they have been sent a secure encrypted message. To read the message, they must enter a previously agreed-upon password. They can then respond to your message so that their response is also E2EE.

How to Encrypt Message for Non-ProtonMail users

1. Compose your message as usual. Any attachments will also be end-to-end encrypted. Before clicking Send, however, click the Encryption button (with the padlock icon).

Composer showing the encryption button

By default, messages sent using the Encrypt Message for Non-ProtonMail users feature will expire 28 days after they are sent. You can change this using the expiration timer

2. Choose and confirm a message password. If you wish, you can also add a password hint to jog your recipient’s memory. Click Set when you are done (or tap Apply if using our Android or iOS apps).

Image of set password

3. Back in the main composer screen, click Send

How to read and respond to an encrypted email

The recipient of a message sent using our Encrypt Message for Non-ProtonMail users feature will receive a regular email explaining that a secure message has been sent to them. To view the message, they must:

1. Click the View Secure Message button.

Email informing you that you have a secure message to view

2. Enter the password that you discussed and agreed upon previously. The password hint option can be very helpful here.

Decrypt message dialogue box where you enter the message password

3. The message will be decrypted locally in their browser for them to read. No one else can read the message.

Text of an end-to-end encrypted email showing its expiry time

4. They can then Reply Securely to the message. This reply is end-to-end encrypted. Full text formatting options are available for this, and any attachments they send will also be end-to-end encrypted.

Secure reply to an end-to-end-encrypted email

Because this is a free service, and in order to combat abuse by spammers, you can only reply to each message a total of five times. 

You can always create a free secure email account to enjoy the benefits of encrypted communication without reply limits and without the need for a message password. Messages between ProtonMail users are automatically encrypted without the need for a message password.

Is this safe?

ProtonMail uses open-source encryption algorithms to secure email communications with end-to-end encryption. This means the messages cannot be intercepted in transit, nor can they be accessed by either ProtonMail or any other email provider. The only people who can read the messages are the sender and recipient.

ProtonMail’s secure messages are safe to open, and it is safe to click on View Secure Message. You can verify the security of the secure message by making sure you’re connected to the official ProtonMail website (and not a phishing site). The domain name should be protonmail.com.

If you want to be extra secure, you can also verify our SSL certificate. Furthermore, you can also check the secure message’s header information to make sure our DKIM and SPF records match what they should be. If you have any doubts, you can contact our security team at security@protonmail.ch.

Encryption made easy

If you also want to send secure messages, you can get a free ProtonMail account. ProtonMail accounts also benefit from automatic end-to-end encryption between ProtonMail accounts, so if you have sensitive communication needs and both parties are using ProtonMail, you can ensure that your communications cannot be intercepted or handed over to third parties.

You can learn more about us or sign up for a free email account. You can also support our service by signing up for a paid account.

Post Comment


  1. LH

    It would be great if external users could reply to these encrypted messages with their own encrypted message without creating a ProtonMail account.

  2. Alex Lo

    Totally agree.

    Another recommended feature is that the receiving party can choose to store the agreed password in the browser so that he/she doesnt have to enter the passport again if I sent him/her another secure email next time.

  3. Swagat

    A password manager like lastpass/1password can be used for this.

  4. CDC

    Can you explain the difference between ProtonMail’s end to end encryption service and the use of Email Certificates? The feature of sending an encrypted outside email is very much symmetric encryption. There appears to be an absence of Email certificates for end users which is a feature of Public Key Infrastructure.

  5. tbtel

    Just to clarify, since it does not say on this page anywhere, outside users CAN send encrypted responses through protonmail. See https://protonmail.com/support/knowledge-base/can-outside-users-respond-to-encrypted-messages/

  6. Foxxy

    Sometimes people do not pay attention :) It is clearly stated that you can “reply securely”.

    “6. Upon entering the password, the message will be decrypted allowing your recipient to view the message and reply securely.”

    “*Please note- The recipient is not asked to download any software or sign up for ProtonMail at any point in this process. It is up to the ProtonMail user to find the most secure manner to communicate the password they have chosen to protect the encrypted message, to the recipient.”

  7. Benjamin Lim

    *Please note- The recipient is not asked to download any software or sign up for ProtonMail at any point in this process. It is up to the ProtonMail user to find the most secure manner to communicate the password they have chosen to protect the encrypted message, to the recipient.

    Well, if I need to have a secure communication channel to communicate the password to the recipient. Then why don’t I just use that channel in the first place and skip protonmail altogether?

  8. Kirchof

    Because this additional secure channel might not be good/convenient for ongoing communications. Suppose you give your password to your target via phone, letter, scrap of paper or simply tell him. That is a once ever operation, and then you can securely email, with all the convenience that the email provides — compared to phoning (both must be available at the same time), mailing (gonna take a while till mail gets physically delivered), talking (must both be physically in one place at the same time).

  9. whitfield

    would like to have the ability to associate a pre-agreed upon password with each non-ProtonMail recipient and store that information with the Contact so that when mail is composed the password information does not have to be manually entered each time.

  10. leslieallen

    It would be good to have a proton mail password key database for those users who cannot seem to remember their passwords… and choose to use a lazy mans way to store their passwords, ie their browser (which is actually very stupid). Which will usually provide a way for others to know their passwords… and eliminates the security they wanted in the first place. Stupid is as stupid does. Ignorance breeds ignorance. I hope you don’t implement the options that I have heard regarding passwords in these postings. But an encrypted password database would be good so that passwords can be stored and easily reached. It would also be a good thing to build into this database a way to send passwords to other users instead of using their phone or other non-secure methods of transferring passwords. People can use Signal or other text methods to pass unsecured passwords in the beginning. But Snail mail is probably the best way to send passwords in the beginning if it is long distance. Also, there should be a way to cause passwords to be changed every few days to force people if they choose it… to change their passwords frequently.
    This is obviously the weakest link in any encryption scheme. I have some ideas for passwords that change every day… with just one initial password exchange in the beginning.

  11. _webkernel_

    it would be nice to be able to send email encrypted and signed with PGP. If I need to pre-agree the password for an encrypted email that is non-sense, because I need another (other) secure way to do it. That is a duplication of means.

  12. Lewis Beeler

    I like the process for sending encrypted email to people who do not have Proton Mail. I am a Christian minister, and I live part time in the USA, and part time in another country. I believe the governments of both countries in which I live attempt to read all international emails. This is not a problem for me today, but I fear that in the near future I will be subject to arrest for distributing Bibles, and other Christian literature. Thank you Proton Mail for your service. People all over the world have the God given right to freedom of thought no matter what their beliefs might be.

  13. Nadia

    Is email sent and received encrypted without using the password? If so, is the password just an added security?

  14. ProtonMail Support

    For the message to be end-to-end encrypted when you send to a non-ProtonMail address you need to add a password.

  15. J.L

    PGP is definitely an obvious and incomprehensible ommision for Protonmail

  16. Suzy

    I would definitely concur: please implement the ability to send OpenPGP, with associated signature. That would slay the competition. So far, this is a great feature. But standard options for encryption and decryption help.

  17. Katelynn

    The process of encrypting messages for non-ProtonMail recipients is too unwieldy to do for the amount of emails that I send and receive daily … as per many of the above comments, I too look forward to a more straight-forward and streamlined way to accomplish end-to-end encryption for emails sent to non-ProtonMail recipients. In the meantime, because it’s unclear to me, can you please explain to what extent emails sent to non-ProtonMmail recipients (and the replies received back from them) are encrypted? Will my outgoing and incoming emails always be encrypted on my end by virtue of the ProtonMail server and my mailbox password? Thanks in advance for your response and support!

  18. ProtonMail Support

    For now this is the only way the messages can be end-to-end encrypted. If you send a regular message to an outside recipient, it is encrypted, and stored encrypted on our side, but we can’t do anything about the recipients side.

  19. Sally

    Has this been fixed? I had a startmail account and I could enter another person’s key and then send to them encrypted without the password hassle.

  20. ProtonMail Support

    PGP support with the option to import contact keys is currently in active development and should be available soon.

  21. Don

    This is great news! Looking forward to it.

  22. Halil

    What happens if one sends an unlocked email (one without a password) to a non-protonmail e-mail address which is also claimed to be secure (e.g., encrypted mailbox)? The message will be encrypted both on sender side and on the recipient side but what about between the servers? Thank you for the service and support.

    PS: In my humble opinion, major anonymous/secure e-mail providers should come-up with a system to send each other encrypted e-mails. I think, locking each email is a tedious and non-sustainable..

  23. ProtonMail Support

    If you send a regular message, with out a password, the message is stored encrypted on our servers but once it leaves our servers it is dependent on the recipients service.

  24. Anonymous

    What happens if an encrypted message sent to an outside user who has the password and decrypts it, then forwards it to another outside user.
    Does it go to them encrypted, or does that break the encryption protection I initiated?

  25. ProtonMail Support

    The message can be only replied to and you cannot change the senders. This means that you cannot forward the message to other recipient.

  26. Darkmatter

    All the person has to do is either highlight and copy/paste the email into a new email or if that is locked out, manually type out the email into a new email.

  27. ProtonMail Support

    This (trust) is a risk with any form of communication and does not apply to the original question. Any message sent this way will not be originating from ProtonMail and is a new message, not a forwarded message.

  28. Denis English

    Well dahhhh…that’s like saying “my password isn’t secure” after you write it up and send it around. Of course you can publicize secrets.

  29. hristo

    Is it possible to try and fetch the PGP key of the recipient of an outside user, if there is one available, and encrypt the message using that? As well as attaching my public key.

  30. ProtonMail Support

    Not yet, but we have plans to do this later.

  31. Robert Laing

    Any progress on this?

  32. DrSnap

    Yes, any progress since 2016?

  33. Frank

    Same question from me.
    With no ability to store (and use) public keys of my most used contacts in a keyring or, better, fetch them from keyservers, the only use for ProtonMail is sending a secure email when I’m nowhere near a trusted device. In all other cases the seamless use of the public keys of my contacts offers so much more:
    * All parties involved can read the email in their usual client, not interrupting the familiar workflow.
    * No need to enter some random password on some website just to read an email.
    * The ability to decrypt messages from years ago (as long as the private key is available of course)

  34. ProtonMail Support

    Full PGP support with importing contact public keys is currently in beta and we hope to have it released in the near future.

  35. Anonymous

    It would be nice if emails in the “sent folder” noted whether the email was sent encrypted and kept a record of the password when sent encrypted to a non-protonmail user.

  36. Nemo

    Is it possible to send unencrypted emails to people who do not have Protonmail (e.g., people with AOL, gmail, iCloud, Yahoo). If it’s possible to send unencrypted emails, will such emails also be stored unencrypted on your servers?

  37. ProtonMail Support

    Messages are always stored encrypted in your mailbox. For more information about what is encrypted when sending messages outside of ProtonMail, take a look at the following article: https://protonmail.com/support/knowledge-base/what-is-encrypted/.

  38. Anonymous


  39. Darkmatter

    If your sending an email to someone who won’t have a decrypt key and your just trying to send an email anonymously does ProtonMail automatically hide the IP address of the emailer so the recipient can’t see your location or no? Also, I decided to be on the safe side to use your free version of your VPN and have it set to route through one of your secure servers. It is currently connected and running, and after I got it up and running I restarted my web browser to make sure it used the VPN. So if the above answer is no, can I assume that by using your VPN the person receiving the email won’t see the correct IP address if they try to look it up?


  40. ProtonMail Support

    Only ProtonMail’s IP address is included in the message headers, user IP addresses are completely safe, even without the use of VPN.

  41. Jan

    This solution is elegant but in a high output-setting a little bit complicated. Would it be possible to include encryption towards extern recipients into the bridge? As an alternative an app would be helpful (or even better) that can be addressed via the send to/share dialogue. Finally saving a strong random password together with the contact and using this automatically for encryption would be awesome.

  42. Dion Moult

    No updates in 2018?

  43. Proton Editor

    We are working on improving encrypted sending for outside users, but we cannot give you an ETA on any changes yet.

  44. pwruzr

    It’s a complex process encryption of non protonmail email services it’s like you have to design IT to do all the work from the proton side without any intervention from the recipient of your sent email SINCE one persons outlook on security vastly differs from the next nothing at all can depend on the recipient since you never can know for sure ahead of time if something was dependant on them that it will be done you have to assume it won’t all you can possibly do to make the recipient is to design IT so they won’t be able to reply to IT, A HUGE ANNOYING siren should suffice….lol this is how I think I can never depend on others to follow thru on a security feature just because I do ..most don’t care so many angles that have to be taken into consideration ..OH I GOT IT MAKE PGP A STANDARD FOR ALL EMAIL AND IF THEY DONT DO OR SKIP A SIMPLE STEP THAT WOULD COMPROMISE THE EMAIL THE SIREN IDEA STILL IS AN OPTION MAKE SIREN OVERRIDE THEIR SPEAKER SETTINGS AND MORE BUT THIS WONT HAPPEN YOU CANT FORCE PEOPLE TO REALIZE WE ARE FACING SERIOUS ISSUES THESE DAYS …LOL OK IM OUT

  45. Denis English

    Thank you for this informative post; I’m starting to understand how it works. I wondered how the sender encrypts the message to be sent; I didn’t know the little symbol says “encrypt this message”! Maybe you could clarify that from the get go. When I push buttons here, there is a delay, maybe because I have the blue light filter on. Whatever the cause, it prevented me from determining the function of the important encryption symbol, so fix that. Thanks.

  46. Jon Postyn

    How can I setup ProtonMail Bridge to work with 2 computers – a desktop (Mac) and a MacBook?
    I would like to use the same email address for both computers.

  47. ProtonMail Support

    To set up the ProtonMail Bridge on multiple computers, you will need to follow the installation and setup instructions for the Bridge found at https://protonmail.com/bridge/install.
    If you need any assistance, please contact our support team at contact@protonmail.ch, via the report bug button or using the support form at https://protonmail.com/support-form.

  48. DrSnap

    Ok, i was testing this out just now. Indeed the encrypted message could be replied to by the outside party, but then, when the protonmail user, replies again THE MESSAGE WILL NOT BE IN THE SAME ENCRYPTED THREAD but will be sent as an unencrypted plain text email. All replies in the thread should be encrypted by that pw BY DEFAULT.

  49. Joe Kocon

    A user can opt “to use regular text to” message someone. See Wikipedia for this simple, clear statement. Proton, I’m considering getting a Proton account so I’m studying the pros and cons. After checking four different sites including this one I went to Wikipedia where I got the short sweet answer. (Try it, you may like it.) Thank you Wikipedia!

  50. Stig Poulsen

    After reading Qs&As and comments in the relevant Support Categories I still can’t figure out the clear answer to the simple question which many others also have posed:more or less indirectly : “Is it with the free version of ProtonMail possible to send to a receiver “outside of ProtonMail” an email which the receiver can open “as usual” to directly read it, without any previuos activity related to “unlocking”/handling passwords/etc ?
    In other words: Is it possible for the receiver to handle emails sent from ProtonMail similarly to emails recieved from “the usual senders” (without peculiar encrypting means) ?

  51. ProtonMail Support

    All ProtonMail users, regardless of which plan they are using, can send messages to non-ProtonMail addresses without using the Encrypt option. Please note that these messages will not be end-to-end encrypted, but they are stored encrypted in the Sent folder. While ProtonMail will not have access to the sent message, the recipient’s mail provider may be able to read the message contents.

  52. Stig Poulsen

    Thank you very much for this answer!
    I think you now have relieved serious concerns from many potential future users, by letting them know that they with ProtonMail can work with different levels of security, and therefore also can communicate “as usual” to receivers not requiring your high security level. The main point here is that your future users now know they only need one email-address with you to handle all emails regardless of seecurity level! Great! Prepare your capacity for an invation of new users!

  53. Damian Meyer

    Why do I have to have a password for every email I want to self destruct? It would be nice if it were a bit more subtle and didn’t draw unwanted attention to the fact the email will disappear. This allows people who would normally just ignore an email until it disappeared to now have the chance to take screen shots or save the email in other ways.

  54. ProtonMail Support

    Message expiration is only available for encrypted messages. If you are sending messages to non-ProtonMail addresses, you need to choose a password in order to send it as an encrypted message. You can read more about message expiration in this article: https://protonmail.com/support/knowledge-base/expiration/

  55. VinziForNow

    It’s a wonder that so many people don’t, even after you explain it to them, that “encryption” is comprised of three parts:
    •Encryption at the sending machine
    •Encryption in transit
    •Decryption at the receiving machine.

    It’s still been useful for me to read through these queries and responses. It did take me some time and practice to feel comfortable with encryption and some of the queries reminded me of my own learning curve.

    I’m not on the ProtonMail staff, just an interested user. I much appreciate protonmail’s attempts to make encryption available to more users.

  56. Timoteo

    The instructions state that a “generic message is delivered….”. I have sent test emails to the intended recipient then to myself at a different e-address to see what was actually being seen on the other end. In all cases only a message asking for the password is sent. There is a “unique link” to open…but only if the recipient already has the password. How does the recipient get the pw if it’s not readable in a secured link that does not itself require the password? How does a sender include a hint if the person receiving the mail doesn’t know the answer, or if it’s a hint other people can decipher easily? Sorry; maybe I’m misreading the instructions every time, or the supposed link is missing only in my case, but I can’t see how this is supposed to work. And the recipient’s key? What do I need to do with that?

  57. ProtonMail Support

    You will need to communicate the password to the recipient through another channel, or you can set a password that can be easily explained to the intended recipient using the Password Hint field, but would be difficult for someone else to guess.
    ProtonMail does not have the option to add public keys for contacts yet, this will become available once full PGP support is implemented.

  58. Anonymous


    how people receive protonmail encrypted end to end with password can open this message if he not know this password ???


  59. ProtonMail Support

    You will need to communicate the password to the recipient through another channel, or you can set a password that can be explained using the Password Hint field. If you use a Hint, please make sure to select a password that cannot be guessed by anyone other than the intended recipient.

  60. HH

    Can the message the external user receives be changed through a template and/or are there other languages than english available?

  61. ProtonMail Support

    The message cannot be changed at this time, only English is available.

  62. Anonymous

    How would the person know the password without having to call them up first?

  63. ProtonMail Support

    To quote the article itself:

    It is up to the ProtonMail user to find the most secure manner to communicate the password they have chosen to protect the encrypted message, to the recipient.

  64. Anonymous

    I think it would be very useful to have an option to set replies to a thread that was previously encrypted to an external email, to be encrypted by default

  65. Noel Robin John Board

    When I send a ProtonMail e mail to my doctor’s secretary at [hidden], she gets it but she is unable to reply using the reply icon? She gets a reply message it is undeliverable??? It also states: The following organization rejected your message:[hidden]
    The same happens when she tries to send an e mail to me using: [hidden]@protonmail.com
    Her e mail is: [hidden]

  66. ProtonMail Support

    Please contact our support team: https://protonmail.com/support-form.

  67. Wifiwolf

    Can i use this function with thunderbird or AppleMail? or is only available for the web version?

  68. ProtonMail Support

    Unfortunately, this is not available with desktop email clients. However, this is possible in both the Android and iOS apps in addition to the web client.

  69. wifiwolf

    Will Torbirdy be still useful with this? or is pointless to have it while having this encryption?

  70. ProtonMail Support

    When you set up your ProtonMail account in Thunderbird via the Bridge, Thunderbird communicates directly with the Bridge on your localhost, so for this specific case, a Tor connection is not necessary.

  71. s

    How can a sender know the password?

  72. ProtonMail Support

    If you’re referring to the recipient, please read the note at the end of the article:
    *Please note- The recipient is not asked to download any software or sign up for ProtonMail at any point in this process. It is up to the ProtonMail user to find the most secure manner to communicate the password they have chosen to protect the encrypted message, to the recipient.

  73. I was never here

    Greetings everyone!

    I was looking for email services, because I was without any provider. After reading about the current state of hacking/maleware/viruses and privacy issue inundation, I believe these are all equally interelated. I became uncomfortable with signing up for most services and found and article about ProtonMail. Liked it was free, to at least test drive the service.

    A few few questions I have regarding, how to deal with verification emails from mobile id accounts and apps? I understood what I read about the need to encrypt secure subject matter, however will encryption work with these compaines for varifications only? I think this is important,for a secondary layer of protection, in case of intrusion into servers of that company requesting verification. Especially considering many, multiple third party apps are infused to a degree. Last question I have is regarding the beta 4.0. If members use the free service, does the beta tryout offer more vpn and mail service features? It would be nice to try the VPN on more then 1 device, considering mobile, desktop pc and routers differ from each other.


  74. ProtonMail Support

    All messages in your mailbox are stored encrypted: https://protonmail.com/support/knowledge-base/what-is-encrypted/.

    Using the Beta doesn’t provide extra features or VPN connections, these are tied to the Plan you’re using, not the version.

Comments are closed.