If an hour's downtime would make you 'seriously consider' switching, I doubt you will find any service that meets your requirements. You're asking for 99.96% uptime. I don't think any email provider will guarantee you that.
99.95% is a high standard already: 365x0.0005x24 is 4.38 hours outage for a year. In our current world, 4.38 hours is certainly not enough time to, say, rebuild a DB from backup, if needed.
Yeah, especially when they're saying it's calculated on a calendar month, so you can't even "draw down" on previous months with 100% uptime if you have a serious outage.
Yes, but I assume the rationale here is that they will only have to refund that month and can reset the clock for the next month. So if they have serious downtime it won't cost them for the full year - just for that one month.
Noone can gurantee any specific uptime. Any projection for the future, however qualified and propable, is still only a projection. GMail could go down tomorrow, for 24 hours or forever. (Not, of course, that such optimism is in way warranted).
Whoever downvoted the comment above start your own server, and we'll talk a decade later. The comment is correct; nobody can guarantee uptime. The can promise, there can be agreements, insurance, etc, but guaranteeing is basically impossible. Even if someone were to use a real mainframe cluster across the globe one still connects to them via international ISPs and those routes can go down as well.
While I agree with the sibling that an hour's downtime isn't much, and that you can't expect much better performance than that, I'd like to give a shoutout to mailbox.org.
I originally chose them over Proton when degooglifying my life because of Proton's absolutely batshit crazy idea not to offer IMAP access. I've been very very happy with mailbox for years. Their web interface is ugly, but like I said… IMAP.
ProtonMail does client side encryption/decryption so there is no way to offer vanilla IMAP endpoints without some sort of client side decryption. This is what ProtonMail Bridge does. Although I'd admit it's not always the most stable experience, depending on your mail client.
It's still a completely pointless cludge, and another thing that can break. For no reason. No reason at all!
I really wanna like and use Proton. I think some of the people behind it are great. I wanna support Swiss companies (I miss the place dearly). I don't mind that it's a bit more expensive than many competitors. BUT I WANT IMAP ACCESS without some crazy converter stuck in between me and my email.
1) That's patently not true. It's their special flavor of encrypted email that's not compatible with IMAP.
2) I value IMAP far far far more than I value their special flavor of encrypted email. If they'd let me turn the latter off in exchange for IMAP without the crazy converter, I'd have chosen Proton when I was cutting Google out of emails.
