Proton is reporting problems with almost all of their service including Proton Mail, VPN, Calendar, Drive, Pass, and Wallet. The only service apparently not effected is SimpleLogin.
See here: https://status.proton.me/
For me, just Proton Mail is down. VPN, Calendar, Drive, and Pass are working. Can’t comment on Wallet as I don’t use it.
Mail is down since an hour for me and Drive is not uploading anything. VPN seems to be working but I will switch to another VPN until they fix everything.
Just went to Proton.me (from Europe, edit: also tried from Taiwan, Australia and South Africa), signin page worked, and
Mail: Failed to connect to server
Calendar: Working
Drive: Working
Pass: Working
VPN: Working
Wallet: Working
Hopefully this outage won’t be like the one in July 2022, when service for some users was interrupted for days. Such major disruptions like that can make people jump back to things like Gmail and never look back.
I hope I won’t lose my incoming emails during this outage 
According to Proton, the 2022 outage was: “…caused by a new authentication default introduced in a recent patch of the database software”
I wonder what root cause of this outage is.
source: Analysis of Proton’s July service disruption | Proton
The way stuff works, is that there are a lot of retries if an email doesn’t arrive to the destination.
As of 16:15 CET, all services other than Mail and Calendar are operating normally.
Back up for me. However, my Windows app updated just before it was back up and now some emails that I delete reappear in my inbox with a ‘Something went wrong’ message! Probably not related, but who knows?
Thankfully Proton Mail is working now for me. Currently Proton webpage says the only service still having issues is Calendar.
Spouse complained that we have no internet… so that was why! VPN was down and I wasnt awake to fix or diagnose it.
Incident report here:
FYI