What is a “Sending Limit”?

Sending limits help to protect ProtonMail’s IP reputation and ensure all messages sent from ProtonMail are delivered in the recipient’s inbox – not the spam folder. Sending limits change based on the reputation of individual ProtonMail accounts. There are many ways to ensure your account has a high sender’s reputation. For instance, upgrading to a yearly paid plan will quickly boost your sending limits. However, behaviors such as bulk emailing or triggering spam complaints will lead to much lower limits. ProtonMail is not designed for bulk/spam emailing.

There are two possible hourly limits ProtonMail accounts can reach. Once a limit is reached, please wait 1 hour before sending again.

  • “Hourly external sending limit reached!” 
  • “Hourly external BCC sending limit reached!”

There are two possible daily limits ProtonMail accounts can reach. Once a limit is reached, please wait 12-24 hours before sending again.

  • “Daily external sending limit reached!”
  • “Daily external BCC sending limit reached!”

Spammer detection message.

  • “You are temporarily banned from sending because of spammy or undeliverable emails.”

In addition to hourly and daily sending limits, ProtonMail implements a smart spam detection system to immediately halt the sending of suspicious accounts. If you receive this detection message, please ensure you are following the tips provided below. You will need to wait 48 hours to continue sending with your account. If you continue to receive this message your account will go under review for deletion. If you believe you have received this message in error, please contact us via the Report Bug.

In special cases, some accounts may have a lower sending limit than the default, such as new email addresses that haven’t built up a good reputation yet. Until the account builds up a good reputation, we recommend that you avoid sending in bulk and using the BCC option too often.

A combination of factors can affect your sending limit. Here are some helpful tips to ensure you avoid hitting the limits:

  • Start using your email address – the more you use it, the higher your limits will become.
  • Encourage your friends to join ProtonMail – sending messages to other ProtonMail addresses has a much higher limit than sending to outside addresses.
  • Upgrade your account – enjoy all the features that come with ProtonMail Plus, including higher sending limits.
  • Don’t send spam – ensure you are only sending to individuals who you know or are expecting your message.
  • Avoid sending to undeliverable addresses.
  • Avoid using BCC in excess.
  • Update all the information within your ProtonMail account settings.
  • Keep your sending below (please note, these limits are suggestions. Your user reputation (as outlined above) is variable and will determine your unique sending limits):
    • Free Plan: 50 messages*/hour and 150 messages*/day
    • Plus Plan: 300 messages*/hour and 1000 messages*/day
    • Professional Plan: User’s discretion
    • Visionary Plan: User’s discretion
  • The maximum number of recipients you can add to an email is 100. But keep in mind that ProtonMail is not designed for bulk mailing.

Please note: Sending Limits do not affect inbound mail (this is unlimited). 

* 10 recipients (any email added to TO, CC, & BCC) within a message counts as 10 unique messages. ProtonMail is currently not designed for high volume sending such as marketing blasts and transactional emails. Any spam sending is a violation of ProtonMail’s Terms and Conditions, making your account subject to review and termination.

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  1. Wlawlor

    “is aloud to send” above should be “is allowed to send” :-)

  2. Anonymous

    You mention a limit on “BCC” but not “CC” is there a limit to “CC”?

  3. Dude

    I am trying to share my new email account with my contact list, I believe I ran up to around 50 emails and was shutdown…this is not cool. 50 is way tooo low.. 200 email a day would be more reasonable. Something needs to be done about this limit, as I have contact groups that are over 50. What can been done about this?

  4. Anon

    How do you detect if an email is spam if you supposedly can’t read the emails?

    I’m sure you can tell if an email is exactly the same, but this sounds sketchy.

  5. ProtonMail Support

    We can’t read the content of the messages, there are multiple criteria on which this is being checked.

  6. Mary T. Fisher

    Mary Fisher here again, I think I must have hit the ‘Send’ button by mistake, as I did receive a reply from my friend. Since I had probably hit the wrong button, there would not have bee a draft copy. Automatic save would be a good feature as you are typing. Sorry for the rant, and keep up the good work and be sure and add more features…just lost my job two weeks ago…

  7. K.

    It would be nice if you’d explain precisely what the spending limits are, and how they are calculated.

    I don’t WANT to violate the limits, but unless i know precisely what they are, how can i avoid triggering them?

    I triggered the sending limits at first because i didn’t know they existed. I had more than 25 recipients in BCC, so i got flagged. Like the poster above, i was simply migrating my contacts from another e-mail account, and giving notice that this would be my new one.

    Later, after a couple more tries, i figured out what was going on and i brought the recipients down to 25, and waited until the time period for violating the limit had passed. Then i sent another message with 25 messages – that one go through.

    Then i tried to send ANOTHER message with 25 recipients, and that one got flagged – and i got shut down, again.

    Then, i waited two or three hours, and tried to send another mail with only 6 or 7 recipients – and THAT one got flagged, and i was shut down again.

    Then, i waited nearly 10 hours (after being told i would be shut down for “1 (more) hour”), and tried to send another one with 8 or 9 recipients – and now, i’m shut down again.

    I’m perfectly happy with abiding by the rules, but unless the rules are clearly stated and consistently enforced then i can’t possibly know how to abide by them.

  8. ProtonMail Support

    There are many criteria based upon an account is flagged as suspicious or spam account. We are working on improving this, so the regular users aren’t affected by this. Also we are working on adding an option for notifying your contacts that you have a new email address, so you won’t get flagged by mistke. If you have more questions you can contact us on contact@protonmail.ch or via the Report bug button.

  9. Don

    I’m glad to see that you are working on a way to make notifying people of my new email address to be exempt from the volume of sent emails. When we first get a proton account, it’s important to be able to let people know.

  10. Monday Precious

    I Subscrip about with 30Euro but i could not send mail morethan 100 email so i really don’t know why i paid 30euro

  11. ProtonMail Support

    Can you please contact us at contact@protonmail.com? ProtonMail is not designed for bulk sending.

  12. Juan

    Dear Sirs: I am testing the free account and trying to send an email, it says “You’ve hit the limit on the number of composers you can have open at once.” can someone explain why ???

  13. ProtonMail Support

    Please try refreshing your browser.

  14. Tom

    I’m trying to notify my contact list of my new protonmail, but I got shut down when I tried to send it to 25 people

  15. ProtonMail Support

    The limitations are based on multiple criteria. If you have questions, or need more information you can contact us via the Report bug button.

  16. Mary Fournier

    What’s the plan to send unlimit. Please answer

  17. ProtonMail Support

    For more information about the sending limit for the paid plans, please follow this link: https://protonmail.com/support/knowledge-base/paid-plans/

  18. Ano_87

    I have around a 110 people in my community, and I would like to send them all a massage in BCC. But after 25 addresses I got a limit notification already. Now sending is frozen for 1 hour.
    Is it considered spam if I send 25 BCC addresses each hour till all contacts are e-mailed?

  19. ProtonMail Support

    ProtonMail is not intended for bulk messaging. You can send the update over a longer period of time, and to a fewer addresses to a single message.

  20. AW

    25 recipients per email is ridiculous low, I sometimes need to sent a email to group up to 50 people.
    I paid €48 but it Proton service seems useless.

  21. ProtonMail Support

    The limits are in place so our service is not abused by spammers.

  22. Tom

    I really understand your good intentions to prevent spammers from using this service, but i think, a spammer will not pay (at least) the plus membership fee to be able to send a maximum of 300 spam mails per hour; there are cheaper ways to do that.
    What remains, is a inconvenient behaviour for all your _paying_ customers: i can not send a message to more than 25 recipients (which is really a low value), and i get flagged, if i send a message to more than 100 recipients.
    Sometimes you just want to send e.g. a mail to 120 friends to invite them to your birthday party.
    If this is considered bulk emailing, then yes, sometimes your customers would like to do that!
    Other (free) email providers do not set such strong limits. I personally believe in your product and would really like to continue to use it, since i believe in strong end-to-end encryption, but if the handling consumes too much time, i’m afraid, you will loose exactly these paying customers, who want to fully replace their (free) email solution.

  23. ProtonMail Support

    We apologize for the inconvenience. Spammers abuse all services and often use stolen credit cards. We have implemented some security measures to prevent the abuse of our service. If your account is blocked, please contact us at contact@protonmail.com.

  24. Jerry

    I must ad that i consider these sending limitations completely ridiculous. I would never have signed up for this mail program if i new i was going to be sanctioned or punished for sending more than 25 or 50 emails per hour or what ever it is. We are your customers not your children to punish. I see people are complaining about this that are paid subscribers or customers, Now i wonder why should i up grade if you are still going to restrict how many emails we can send??? It appears that you (proton mail) think we should not have more than 25 people that we care about and want to inform about things that are happening in the world. One more this is completely ridiculous.
    I do not and have not ever knowingly spammed any one.

  25. ProtonMail Support

    ProtonMail is not intended for bulk messaging. The accounts have sending limits to prevent abuse. The premium accounts have higher limits, but they still have limits.

  26. Sandra

    The 25 recipient limit is really too low. I am using this account to communicate amongst parents in a primary school class. It can in now way be classified as “bulk messaging”!!!!!! Please raise this limit to at least 50 or more email messages. I am on a paid account.

  27. Anonymous

    I’m on a paid account and am using this for private communications for a political campaign.

    Without a basic mailing list which should be a simple service I absolutely require a lot more than 25-50 addresses to send out emails. This was never advertised before I paid for the account and I cannot use personal email services which buy/sell my information without second thought.

    Based on the replies from Proton on this thread it sounds like this will never be an offered service for such items and the company would prefer not tot advertise the limitations upfront before we drain our wallets and scramble to figure out why we get locked out of a simple email service.

  28. Anonymous

    Dear Sir/Madam,

    I’m using my proton mail since from 4 months, i just got a error message that my account has disabled due to spam or fraud. I do have important mails and follow up conversations with this domain. So please kindly help me to sort out my proton mail back. I really appreciate your help and suggestions.


  29. ProtonMail Support

    Please write to abuse@protonmail.ch

  30. John

    Bulk emails can often be avoided, like if you have a birthday party just use Facebook to tell people. For work collaboration tools like Slack and Basecamp are much better suited for online communication.

  31. lkheavy

    I’m trying to send an email, for average 25 recipients (send limit has not been reached), but I every time shows a message telling me that I hit the send limit and i’m blocked for 1 hour. 1 hour later I try again, but the same thing happens…

  32. SolSeek

    If the limit is 10, why can’t I send 9?

    You say:
    “* 10 recipients (any email added to TO, CC, & BCC) within a message counts as 10 unique messages. ProtonMail is currently not designed for high volume sending such as marketing blasts and transactional emails. Any spam sending is a violation of ProtonMail’s Terms and Conditions, making your account subject to review and termination.”

    Rate This Article
    Helpful Not Helpful
    (65 out of 119 people found this article helpful)

    So 45% have this problem.

  33. Michele

    I was trying to send a New Years update to a large number of family and friends. At the same time I was updating my address. I prefer to use BCC so that each person doesn’t get everyone else’s address. Now I can’t tell which ones even got the email before I was cut off because I can’t read the names. It wasn’t spam. Frustrating!

  34. ProtonMail Support

    Please contact our support team at contact@protonmail.com or using the support form at https://protonmail.com/support-form.

  35. Luis

    I am a paid Plus member and needed to send a vital message to my community today. It did not send. The app did not give an error, it acted like it sent, it just didn’t. And it took me hours to figure out why, after trying many times… it was blocked because there is a limit of 25 recipients and I had a list of about 40.

    I don’t send mail to groups often, but today was vital. This was a big disappointment from your service, which up until now I had been actively endorsing. I had to go back to my old email account and copy my proton address.

  36. Cath

    It is a good idea to limit the sending of mails because of spammer protonmail would be in Black list of other mailboxes. E-mail coming from protonmail would be systematically suspected as frumpy by Gmail or Outlook.

  37. Joe

    Gmail or Outlook blacklisting Protonmail would be like Al Capone blacklisting Elliott Ness.

  38. david

    you say 25 is sending limit per hour
    yesterday sent 25 was blocked
    today sent 25 blocked again
    both times just ONE EMAIL to advise address change
    this is crazy
    you say i can send 25 but then you block it

  39. Proton Editor

    The sending limits are different for each user. The longer you use your account, the higher your sending limit becomes. If your account is blocked, please contact us at contact@protonmail.com or using the support form at https://protonmail.com/support-form.

  40. Joe

    We are having trouble with the limit as well. We have 75 people on a mailing list that we send out maybe two or three times a week. Maybe there is a way to vet a mailing list in order to preclude its use by spammers?

    Other than this limit, we love protonmail. My wife and I both have paid plans.

  41. Joe

    The Sending Limit is a bit of a nuisance. We send out one to three emails a week to a fixed list of about 75 church members. Since we started using Protonmail, it’s become a bit of a chore. You’re clearly more familiar with spammers’ methods than I am, but there must be a way to differentiate between spam and legitimate multiple recipients. What if the recipients were to reply affirmatively to a request from an email list with the ability to opt out at any time? Anyway, keep up the good work. Better secure than sorry. My wife and I both have paid accounts.

  42. Marc W

    I’m a Visionary account holder but still limited to 25 recipients in an email chain which is ridiculously low – and embarrassing to have to apologize to everybody about Protonmail’s limitations on email recipients Vs every other provider out there. Please review this limitation ASAP!

  43. Justin Emery

    This 25 emails limit is concerning. I wouldn’t send to this many people myself, but I can’t even reply all to an existing email I was sent with 30 people CCed.

  44. Dale Brandt

    Is there a limit on the size of an email attachment ? If so, what is it ?

    Is this limited by ProtonMail’s webmail or my ISP (e.g., COX) ? From what I know, COX has an email size limit of 20 MB (small). Is there a workaround to increase this limit via using ProtonMail ?

    Thank you

  45. ProtonMail Support

    The attachment size limit in ProtonMail is 25 MB. Please keep in mind that attachment size may increase after encryption, so the effective size limit is a bit lower. If the recipient server has a lower attachment size limit, it may reject messages that do not conform to their size limits.

  46. Peter

    This is, bar none, the stupidest policy I have encountered in a long time, anywhere, and is enough to make me reconsider my decision to PAY you for my premium acct.

    I am not a spammer. But, occasionally, ppl DO need to send emails to, e.g.,, 30+ recipients — such as when organizing transportation for a middle-school class for a field trip. Give me a break. So now not only can I not send my email, I’m also barred from sending ANY email for a full hour? What are you, the internet nanny?

    Seems very un-Swiss of you to believe in the nanny state. Very odd.

    Now re-considering the PAID professional acct that I have with you….

  47. ProtonMail Support

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

  48. Bruno

    Hi !

    I’m glad to join this community, but my beginning is a bit disappointing : for my first mail I had 10 adresses to send to, and I got a sending limit message. Then I tried with only two, and again same message : sending limit. Then I tried with only one adress : same problem. So how shall I use protonmail with less than one recipient ? I’ve seen that by using protonmail regularly it would increase the limit, but how can I start if even 1 recipient is too much ???

  49. ProtonMail Support

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

  50. gustavo

    my box just went frozen.
    can messages still enter to the ones have messaged before.

  51. ProtonMail Support

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

  52. DNP

    Upgraded to a plus plan so we could send 260 news organisations an press release. Ideally all should have received it simultaneously. First attempt to send all in one email was flagged as too many recipients. Broke the list into three. 1st went out, second was flagged for too many emails in one day – sending blocked for one hour. Reported this and waited an hour to send the rest. After last batch went out, we have now been flagged and stopped from sending for another 11 hours. VERY UNHAPPY ABOUT THE UPGRADE EXPERIENCE BUT LOVED THE FREE SERVICE. We look pretty stupid if we cannot reply to responses to our own press release. It is NOT at all what I would have expected from protonmail. And, I have already gotten tens of people to join…

  53. ProtonMail Support

    Sorry for the inconvenience. Be advised that ProtonMail is not meant for bulk sending and sending of newsletters/transactional emails, as noted in the article.

  54. Det Nye Partiet

    This is beyond belief. Had I known about this in advance, I would not have upgraded our account. What in the world is the logic in paying for a service that limits you to less than what it tells you you can do?

    The plus package clearly states send 1000 emails per day.

    This package was purchased today around 9 a.m. local time.

    We have sent less than 300 emails before 12 noon, but cannot send a single other email to anyone else today!

    First we were shut down for an hour for sending 90 emails. Then we were shut down for 12 hours, when we sent the other 170 we needed to.
    Sending took about 10 minutes. Otherwise we cannot use the service for another 7 hours or so? EPIC FAIL

    Total time unable to use the service we are paying for? 99.99% so far. Actually more than 100% because we will not be able to use it for several hours yet.

    That is outrageously poor service and as far as I am concerned a breach of contracted terms of service. Certainly false advertising based on the fact that the plus package explicitly states 1000 emails per day.

  55. ProtonMail Support

    These limits are for non-bulk messages. Sending messages in bulk can still result in sending being restricted. ProtonMail is not meant for bulk sending. You can contact our Abuse team (abuse(at)protonmail.com) and they can help if the messages you’re sending aren’t found to be spam.

  56. Olawale

    what’s the limit on sending mails . I have not been able to compose any further mails as I keep getting a message that I had reached my limit . Is this a daily limit or weekly ?
    thanks Ola

  57. ProtonMail Support

    Sending limits are different for all users and depend on several criteria. Note that limits for newer accounts are lower at the beginning.

  58. yiyi

    What is your definition “Avoid using BCC in excess” and “bulk emailing or spamming”.
    I should tell all contact about my new email.
    I just send to 10 persons in BCC. same messages twice, you limit my email. It isn’t reasonable.
    I can’t realize your guidelines.

  59. ProtonMail Support

    If you have a brand new account, your sending limit will take a while to increase.

  60. Emily

    What is Heck’s name does Composer Maximum reached? I am dipping my toe into proton mail, have the free account, should have 150 email allowed a day, had not sent one when this “COMPOSER MAXIMUM” reached notice goes up. What the hey?

    Back to lousy gmail. bummer.

  61. ProtonMail Support

    You can only open three composer windows at the same time. Trying to open more will trigger this warning. If you see this warning and don’t already have three open composers, please contact our support team: https://protonmail.com/support-form.

  62. Ed Snider

    I am new to protonmail and cannot learn where I write a message to be sent; what do I do?

  63. ProtonMail Support

    Click on the COMPOSE button in the web client or the pencil icon in the mobile apps.

  64. will

    are you finding the app confusing? I believe in the “keep it simple “way and do not want to rely on this app if too much thinking is involved. :]

  65. Anonymous

    Well, I want trying to spam. But had around 10 names each in TO and BCC, for a valid reason. I didn’t get enough time to read the popup message regarding the limit. So, tried sending again and for banned for an hour.
    I agree with your reason for not showing it and really appreciate this rule. But, could you please improve on those popup messaging time.
    Thank you for the service.

  66. Ep

    I have not even send not 1 email, but I cannot send anything ???

  67. ProtonMail Support

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

  68. Chuck Sheketoff

    I have a list of people who signed a petition who want to be kept informed. Right now the list is 56 names – in the future it may get up to 500. I’d like to be able to protect their privacy by sending to the group via bcc – how can I do that with your limits?

  69. ProtonMail Support

    The maximum number of recipients per message is 100. Paid users can create contact groups of up to 100 recipients and send to the group without needing to add each recipient manually. However, note that this will still count as 100 separate emails toward the limit.

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