r/ProtonMail 4d ago

Announcement August 27 outage: Incident report

1.4k Upvotes

In the early hours of August 27, 2026, Proton experienced a widespread outage that impacted services for a number of users. The root cause was a total failure of the cooling system in our Frankfurt datacenter. While all systems at Proton are redundant and we have enough capacity to endure a complete data center failure, there are a small number of scenarios where the failover can take longer and lead to user-facing disruptions.

Here’s a timeline of what happened, what choices we made during the incident and why, and how it was resolved.

Timeline

Just after 11 p.m. (Central European time) on Wednesday, August 26, a cooling system failure occurred in the main room of our Frankfurt datacenter. At around 11:15 p.m., the temperature started rising from approximately 21.8°C (nominal temperature) to 51.9°C in less than half an hour, with some measurement probes reporting 60°C air temperature in the room. As the temperatures rose, server and networking equipment within the facility started to die one by one.

The user-facing incident began at around midnight on August 27, when the failures escalated to the point that critical redundancy was lost. This occurred when both the primary and backup network switch on a critical rack failed, and this rack unfortunately contained several primary database copies. While almost all Proton systems are redundant and will failover automatically/immediately, primary database failovers are not done automatically without human supervision.

We retain this control out of a desire to avoid so-called “split brain” situations, where a temporary unavailability of a primary database means that the replica copies miss some updates and become de-synced in ways that can be difficult to reconcile later. Furthermore, when a primary database failover occurs, the standard operating procedure is to failover to a replica in the same datacenter for latency and performance reasons. However, the specific nature of the problem meant that this might be ill-advised, since we potentially could be failing over to something that would also go down.

The decisions

At this point, Proton’s on-call engineers needed to make a couple consequential decisions while operating under extreme pressure.

  • Do they prioritize bringing the service back online, or prioritize addressing the cooling problem and saving the hardware inside the datacenter?
  • Should we failover to replicas within the same building Frankfurt (faster and less disruptive, but possibly a temporary fix if the heat could not be brought under control), or failover to Zurich?
  • Do we failover everything or just what is down at the moment? We have contingencies for complete data center failure where things failover fully and mostly automatically rather quickly, but a situation where random servers are dying one by one is not handled well by our failover logic.

Ultimately the rate at which temperatures were rising forced us to prioritize saving the hardware versus bringing services back online. This is not a choice that typically needs to be made, because cooling systems are typically redundant, and the complete loss of cooling is quite rare, meaning that there is quite a bit of time before temperatures become critical. The problem is exacerbated by large increase in server power density in recent years with higher power CPUs and GPUs for AI. As a result, what used to take 3-4 hours to go critical went critical in 20 minutes.

The on-call team therefore focused their attention on communicating with the on-site datacenter operations team to restore cooling while powering off as many servers as possible to protect them. Due to a server equipment shortage tied to the ongoing AI boom, lots of this equipment — if lost — would not be possible to replace on short timelines. Saving it had to be a priority, even at the cost of potentially extending the downtime.

By 00:45 CEST, we were able to restore cooling and temperatures at the facility began to drop, and the on-call team switched focus to service recovery. At this point, we made the decision to failover the primary databases to Frankfurt if a replica was still alive, and to Zurich in cases where there was no replica alive in Frankfurt, to avoid changing our traffic flows too much and possibly creating new instability. This option was selected because we assumed that, now that we had the cooling under control, it would be relatively easy to bring Frankfurt back online and faster than switching over to Zurich.

Unfortunately, this turned out not to be the case. During the incident, many network cards in the Frankfurt infrastructure reached a temperature of 105C (normal operating temperature is 45C), which triggers a special temperature protection mode and causes the network cards to be disabled until there is a cold system reset. Our security posture limits the ability to access the out-of-band controller for our systems, which required us to wake up additional staff to assist with the recovery.

By 01:30 CEST, we were able to get most services back online for most users. However, some less critical systems, such as push notifications or payment processing, were not recovered until around 02:00 CEST.

As we reported during the initial incident report, no emails were lost, but email delivery in both directions was delayed during the incident.

While user-facing services were fully restored, that was not the end of the night for our engineers, in particular the database team. Our infrastructure was left in a highly abnormal state, with some primary databases in Zurich and others in Frankfurt, and several of them operating with reduced redundancy and/or reduced performance. Our team worked through the night to resolve the most pressing of these issues, and the work continued through the day on August 27 to restore full redundancy.

While we were able to save almost all of the infrastructure, some servers unfortunately suffered heat death, and we don’t know yet if the heating incident will impact the lifespan of the surviving equipment.

Root cause and next steps

A subsequent investigation on August 27 traced the root cause of the cooling failure to an air filter replacement on both of the redundant air compressors powering the cooling system. Unfortunately, the datacenter operator performed this operation in the middle of the night, without prior notice, and also failed to communicate the cooling failure when it happened, which dramatically cut down the time we had to respond. We are working closely with the operator to prevent a repeat of this incident.

However, it is also a known limitation of our current database infrastructure that an outage of this type could lead to a longer than normal recovery process. The series of events that led to this incident are highly improbable — yet they happened.

The database resilience work required to address this failure mode is already underway and remains planned for completion by the end of the year. Additional infrastructure capacity, including new datacenter space, is also currently being commissioned and is expected to become available within the next few weeks, which will further reduce our single site dependency.

Unfortunately, this incident occurred before those improvements were fully in place. We are now reviewing where we can safely accelerate the remaining work while maintaining the level of care required for changes to critical database infrastructure.

We recognize that our users expect a very high level of reliability from Proton, and this incident reinforces the importance of completing this work and continuing to raise our resilience standards. We apologize again, unreservedly, to every user who was impacted.

Thank you for your continued support,

Bart Butler


r/ProtonMail 12d ago

Announcement Introducing categories in Proton Mail

391 Upvotes

Hi everyone,

We’ve added Categories to Proton Mail to reduce inbox noise and make important emails easier to find.

Incoming emails can now be automatically sorted into:

- Primary

- Social

- Promotions

- Newsletters

- Transactions

- Updates

Newsletters and Transactions are unique to Proton Mail, we added them to give you more granular control over your inbox.

Categories are on by default for new users. Existing users will be asked whether they want to turn Categories on, and you can choose which categories you want to see in settings.

What you can do:

- Move any email to a different category at any time (doing so will allow the model to learn from your preferred categorization)

- Control unread counts and notifications per category

- Turn off any category individually, or disable the feature entirely in settings

On mobile you can disable them in Settings → Mailbox Preferences → Categories → Disable

On web: All Settings → Messages and composing → Email Categories → Disable

You may also notice an updated inbox toolbar as part of this change.

From a privacy perspective, enabling Categories doesn’t change anything about how Proton Mail works.Your inbox remains protected by zero-access encryption, and emails you send to other Proton users (or using password protection) are end-to-end encrypted.

Learn more: https://proton.me/blog/proton-mail-categories

Try it out and let us know what you think in the comments below.

Proton Team

https://reddit.com/link/1vtlczf/video/unqo4y11ojkh1/player


r/ProtonMail 11h ago

Web Help Is Proton down again?

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372 Upvotes

Status page says it’s fine but both Pass and Mail are down for me 🤷‍♂️


r/ProtonMail 9h ago

Discussion Proton Services Status - Service disruption

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225 Upvotes

r/ProtonMail 2h ago

Discussion Holy macro notifications....

40 Upvotes

They just keep coming and coming, my phone going nutz... (on android)

Anyone else? Looks like due to recent downtime, email notifications are catching up... 🤪


r/ProtonMail 14h ago

Changes in inactivity policy

170 Upvotes

Just a FYI for the community. After reviewing some feedback, the inactivity period at Proton is being extended to 2 years instead of 1 year. If you are reserving an account for your kid (or someone else), please use this system, it lets you reserve a username for 15 years: https://proton.me/support/mail-reservation-voucher


r/ProtonMail 14h ago

Feature Request Proton Contacts needs to be its own standalone app

117 Upvotes

I know this has been talked to death, but after seeing the recent Proton Ask Me Anything comments about contacts and contact sync finally sitting on the 2027 roadmap, I wanted to bring up the standalone app debate. The team mentioned they haven't decided if it will be a dedicated app or just a shared module inside existing apps.

Please, please make it a standalone app.

Here is the underlying issue: native OS contacts are a privacy nightmare. Whether you are on iOS or Android, your cloud-synced contacts are not end-to-end encrypted. Even if you use Apple's Advanced Data Protection, they specifically exclude contacts because of legacy CardDAV support. Plus, if you leave everything in the native phone address book, every random app you install begs for full access to harvest your social graph.

Right now, using Proton Contacts inside the Mail app is just too cluttered. Because there is no dedicated space, my actual real-life phone numbers get mixed together with every single random email address I have ever replied to. It makes managing a true phonebook impossible.

Having a dedicated, FOSS, E2EE Proton Contacts app that acts as a secure vault isolated from the OS would be incredible. It would let us finally delete people from iCloud or Google and keep them safe. A simple background sync tool that just dumps everything back into the unencrypted Apple/Google address book completely defeats the purpose of sandboxing the data in the first place.

Does anyone know if the team is leaning one way or the other yet? And for everyone else waiting on this, do you prefer a standalone app or just better integration with the native OS?


r/ProtonMail 2h ago

Feature Request Folders for Multiple Emails/Aliases

3 Upvotes

Hi all,

I didn't see my answer in any previous posts.

I have one Proton Mail account, which I have imported a personal Gmail to (that I plan to fully let go of once I switch everything to my Proton email), but then I also have work emails, and my own business emails from my custom domain, etc.

Am I missing the setting to have the folders separated by email address? Like in Apple Mail, it shows my personal email name, and then all the folders for that email, and then below that is a business email name, and all the folders for that email.

With only having the ability for two sub-folder levels, I don't always have enough levels to do it manually with the parent folder named for the email.


r/ProtonMail 5h ago

Desktop Help Compose window too bright

6 Upvotes

Using the proton mail app on my computer, the compose window is way too bright. I have cataracts, waiting on surgery, and can't see a thing. Is there a dark mode for the window or am I out of luck?


r/ProtonMail 6h ago

Possible bug Recurring event weekday on calendar shows S - Th, not M-F?

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4 Upvotes

Hi there. Trying to schedule a daily recurring meeting but weekday goes from Sun to Thu; think that should be Mon to Fri? Bug, or am I tripping? Thanks. MacOS both on browser and the app.


r/ProtonMail 7h ago

Web Help Question about mailbox encryption

3 Upvotes

After I change my password PM stopped asking me the second password for "de-cryption" of the mailbox.

If I enable it again, my current mails will be lost?


r/ProtonMail 2h ago

Discussion private Google calendar

1 Upvotes

Hi. Is it possible to use my work calendar (from company google account) within Proton Calendar? I'm not quiet sure I'm able to import it like Proton docs say...


r/ProtonMail 18h ago

Discussion Proton - any happy family plan users?

14 Upvotes

I am an unlimited user, it has worked well for me. I purchased it primarily for mail, VPN, and the ability to add custom domains so it's good value.

I'd like to add a mailbox for my wife and son, which more than doubles the cost. There's a lot of apps bundled in with this, but none that we will actually use other than VPN, mail and custom domains.

If you're using the family plan I'd appreciate some feedback as to how it works for you, and whether you have a similar use case or went all-in on the proton ecosystem.


r/ProtonMail 11h ago

Web Help Old email account

3 Upvotes

Hey there, i just created a proton mail account and as i was trying to do the Gmail thing to bring everything over, it said it was connected to another proton mail account. The problem is i don’t remember what that email is, although it might’ve been just for the VPN. I’m not sure, but is there anyway to find that info so i can delete and start fresh with the one i just created? Thanks.


r/ProtonMail 1d ago

Discussion Is this a good deal ?

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18 Upvotes

So I am planning to get unlimited plan soon since I am eyeing degoogle and using a nice alternative. I have been using protonmail and pass since a year or so and thinking to go all in. Today this deal popped up in web for me and was wondering if this is a good deal on par with Black Friday or not ?

Any thoughts or suggestions?


r/ProtonMail 14h ago

Feature Request App Lock (PIN) for Proton Calendar?

2 Upvotes

User of Proton Mail (free) for > 4 years and possibly moving to paid plan soon. I realise that there still isn't an app lock/PIN protection for Proton Calendar on iOS.

I would love to see app lock in Proton Calendar, as with what was already done for Proton Mail and Proton Drive, for added security. Or if not, at least let me view the Calendar within Proton Mail?

Thank you.


r/ProtonMail 1d ago

Feature Request Post-mortem scheduled email

16 Upvotes

Hello,

I'd like to propose an enhancement to the current Emergency Contacts feature, specifically for situations where the account owner becomes incapacitated or passes away.

I think there is an opportunity to make it more flexible by allowing information to be securely shared with people who do not have a Proton account, while also giving them more direct access to the information they need.

This design is in a way similar to what Google does:

  • I can configure a period of inactivity after which an email is automatically released to one or more designated recipients.
  • The message would be encrypted/password protected, with the password being something I can provide to my loved ones in advance.
  • The inactivity period could be configurable, for example 90 days, 6 months, 1 year, etc.
  • Before the message is released, Proton could periodically notify me and give me the opportunity to confirm that I am still active and cancel/reset the countdown.
  • Recipients would not need to have a Proton account.
  • Ideally, the recipient would receive a simple, secure way to access the information without having to create a Proton account or understand Proton's encryption system.

Why I think this would be useful

I currently keep access to my important accounts and digital assets in a password manager. In the event of my death, my family may not know where to find this information or how to access it even if they get access to my Proton account (using the current feature). Moreover this message could also contain other information that I would want my family to have access to, such as instructions regarding digital assets, important contacts, personal wishes, or where physical documents are stored.

The important part is that the information is prepared while I am alive, but only becomes available if I stop confirming that I am still active.


r/ProtonMail 1d ago

Discussion Websites/companies not accepting proton.me

83 Upvotes

I have Proton since past week and i don't have troubles with Proton. Only trying to switch some of my important accounts to my new mail. Only i've found some websites don't accept @proton.me as a valid adress, like Xiaomi. Is this a common issue?

If so, is there any workaround, without linking my old maildres with Proton?


r/ProtonMail 8h ago

Possible bug This is unacceptable

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0 Upvotes

r/ProtonMail 14h ago

Possible bug Can't send mail to weird email addresses

0 Upvotes

Apparently sourcehut uses a slash in their email addresses and the specific address also has a tilde in it because sourcehut doesn't sanitize it.

ProtonMail seems to just strip these characters out, which breaks email addresses that shouldn't contain weird characters in the first place. But it's technically part of the standard to allow / and ~ in email addresses, but Proton doesn't support sending to such addresses.

Might as well allow #$%&'*=?^`{|} while we're at it. Don't allow users to use these in Proton addresses tho.

Also, please add sending as plain text on mobile.


r/ProtonMail 6h ago

Discussion Anyone else now very much regretting recommending ProtonMail to other people?

0 Upvotes

I brought 4 paid users + 2 small companies (mine included in these) to Proton. Makes me feel like an idiot. Usually the stuff I recommend is reliable and everyone loves it, but email going down this often is not really acceptable to people who rely on it. Makes me kinda sad that this seems to happen this often (and today lasting for so long, I have business to do and I can't receive the stupid magic links....).


r/ProtonMail 2d ago

Discussion How is your overall experience with Proton Mail?

65 Upvotes

Probably every 4-6 months for the last couple years I′ll come to this sub to help me determine if I′m ready to switch to Proton. Every time I leave a little disappointed.

I always see posts or comments about annoying bugs, missing basic features, certain features exisiting on iOS but not Android, or on the web app but not mobile, etc., or things that were promsied years ago and still aren′t here.

It always seems like it′s almost ready. Am I wrong? I′d really love to leave gmail, but I′m still not convinced.

Edit: Thanks for all the great responses!


r/ProtonMail 2d ago

Feature Request Device-Bound Session Tokens

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44 Upvotes

Please add device-bound sessions/tokens. I don’t want stolen cookies or tokens to be usable on another device.

The goal: stealing a session token should not be enough to access the account. The session should be cryptographically bound to the device that created it.

This would be especially valuable for protecting Proton accounts against infostealers, session-cookie theft and token replay, while still allowing users to have multiple legitimate devices.


r/ProtonMail 1d ago

Discussion UPGRADE HELP ? ? ? ? ? ?

0 Upvotes

Current Plan is Proton Mail Plus (1 user), and we want to "upgrade" to Proton Business Workspace Standard (1 user, with the possibility of adding another user to the mix).

The burning question is:
(i) Is the "upgrade" seamless? i.e., all of the current emails, docs on Drive, will remain and continue to be accessible as with current plan;

Additionally, perhaps the real burning question is, how does a current Proton account get "help and guidance" from Proton, in regards to this type of upgrade?

PS. the "advice" to use the "contact" link first, is actually garbage, as this does NOT seem to pertain to UPGRADE questions/needs.


r/ProtonMail 2d ago

Lovebomb ProtonMail Category View - Feedback Report

17 Upvotes

I wanted to offer some feedback on the recently-implemented and long-awaited Category View feature.

First off - a big THANK YOU to the Proton team for this implementation. This was a key feature I needed to stay on top of my demanding inbox as a "zero-inbox"er and continue with Proton Mail. I know it had been in development for a while and wanted to start off with my thanks.

Positive's:

  1. I love the number of and current category types. Transactions is especially helpful if I am looking for my emailed receipts and can have them in one place
  2. Updates is a big positive for a category. Always loved how it worked on Gmail and great to see it included here.
  3. Toggle Off option - While I will never personally turn off this view, Proton's inclusion of the choice to turn this off represents Proton's commitment to give its users privacy and choice and wanted to ensure this was recognized.

Improvements' I'd like to see in Future Updates:

  1. Create, Modify, and Disable Categories -- I have at least 2 or 3 other custom categories I would love to add one day.
  2. Turn off Badges on iOS for Emails in All Categories (Except Primary) -- Only a minor complaint here, but on iOS, I am used to badges for unread messages in my Primary inbox only. Mail in my Social, Promotions, and Newsletters count towards my badge count, and would prefer otherwise.

In Summary: Incredible to finally have this and I love Category View's initial implementation. Look forward to the other future features on the roadmap!