Imagine needing to use your email right now for something critical such as a QR code someone just sent to you to check in somewhere. I'd be lying if I were to say I wasn't going to watch how this unfolds closely. Our engineering team is currently conducting a root cause analysis and for transparency, we will be sharing results on the Proton blog after our investigation is complete. We apologize deeply for this issue and thank you again for your understanding. We have now put a number of safeguards in place, and will continue to improve the reliability of our infrastructure to guard against this type of issue in the future. This result of this was an extended period of intermittent outages and performance issues while we tried to work around the issue. Furthermore, because this was a major software and operating system upgrade, there was no way to roll back the software update. Unfortunately, this issue only appeared under high loads which we were not able to fully simulate in testing. We are still investigating the issue, but what we can share so far is that the technical difficulties were caused by a software update that was conducted over the weekend which adversely impacted the performance of certain systems.
Due to our redundant infrastructure, emails that were not immediately delivered were queued and automatically redelivered. We can confirm that no data and no emails were lost. As of 2:45 am GMT+2, all emails and notifications are caught up, but we are continuing to monitor the situation in case of further faults. During this period, incoming email, outgoing email, and push notifications were also temporarily delayed. Yesterday we unfortunately experienced technical difficulties that caused all Proton services to be offline intermittently throughout the late afternoon and evening European time.