I strongly recommend FastMail over ProtonMail. ProtonMail doesn't support SMTP or IMAP (standard protocols that are a basic requirement of an email service) without using paid, proprietary software which only supports some platforms and is a major pain to use. They also require a proprietary app to read email on your phone. ProtonMail also makes questionable tradeoffs in the name of questionable security gains.
The IMAP/SMTP issue is the main one. The stated reason they do it is to decrypt/encrypt incoming/outgoing emails on the client rather than on their servers. But the problem with that is that decrypting emails on the client is well supported by PGP in almost every email client, and even if an unencrypted email is sent with SMTP you can easily add encryption on the fly server-side - something they already do for incoming, unencrypted emails. So the tradeoffs don't make sense, it's just a convenient excuse which allows them to take advantage of vendor lock-in.
They also make promises which are based on trusting ProtonMail rather than trusting the math that underlies their security model - for example, they could trivially store a copy of incoming emails in plaintext before encrypting them normally, and they could then keep your emails in plaintext without you being any the wiser. Users who depend on their communications being private shouldn't rely on this, PGP does not require trust from anyone but the sender and recipient and has been working well for years. If they wanted to improve ease-of-use for PGP they should have done that, rather than building their own crap with questionable security promises on top of it.
In the past 3 months I have setup accounts on all three of FastMail, HushMail, and ProtonMail. I was mainly interested in having an account with a custom domain. I used the domains I got through Amazon AWS Route53. ProtonMail was the only one I could not setup custom domain on. It would get stuck in the TXT field verification step. I contacted their support and they were not interested in helping me figure out what's going on. They just told me that was AWS problem and I needed to contact AWS support. I cancelled that account. I only used it for about 3 weeks, and my impression is that it was least polished (web UI and iOS app-wise) of the 3. FastMail was the best.
I've also had bad luck with ProtonMail support, such as I send them an inquiry and they never reply back. This definitely doesn't build confidence in the service.
Personally, I'm unwilling to use a mail provider that does not offer standard IMAP and SMTP. So I use Fastmail. (And I've been using them since 2002. Is this what being a hipster feels like?)
IMAP is far too chatty, latency kills performance due to numerous round trips. It might be a standard, it might be open, but it's far from optimal. New standards will replace it (hopefully) https://jmap.io/.
FTP has same problem. Telnet was once a standard, time-proven, open protocols - does anyone have preference for that?
You can polish a turd by wrapping it in secure socket (SMTP over TLS etc..), but doesn't address the underlying issues with protocols that were designed for a day long passed.
AFAIK fastmail is driving jmap as a new standard - because they like standards - but like everyone that works with imap implementation for any length of time - don't like imap very much. (That's just an observation based on imap server and client implementations).
I think they both have there pros and cons, however I would like to emphasize having both around. It really does make for a healthy email ecosystem which prevents larger market holders from changing the federated standard.
I've switched to RunBox. Custom domains are supported; they're based in Norway. The web interface is very basic (I think they're about to release a new version), but I prefer IMAP anyway.
I'm quite happy with ProtonMail, it does what I need (folders, receives emails, privacy). The bridge is also quite neat and I set it up so I can use offlineimap with it so I get backups of all my mail...
Regardless of which you pick, I do recommend to look into getting a personal mail domain, then it's yours.
The ProtonMail mobile app on Android isn't very good. Swiping emails to archive is very slow and often messes up. Sometimes after archiving an email, it randomly reappears in the list until I manually refresh again. Just a lot of little annoyances such as these has turned me off from ProtonMail.
Also, if you want to have Calendar integration, there is none in ProtonMail.
I am sorry I am pasting an article instead of making my own point but the fact remains that just because it's Switzerland doesn't meant it's any better.
I'd add to that, a possible single point of failure for us as users: CEO Bron Gondwana. Bron also shares out his own time for a technical standards effort -- "JMAP".
OTOH, if you're in the US, the next step up in perceived national security threat might well see Protonmail getting blocked. Fastmail, with five eyes on it, maybe not so likely to just "disappear".
Since encryption (and decryption) is done by client-side Javascript, and you don't want them to run Javascript, how would you prefer the encryption be done?
I was looking on my dashboard and seems that bitcoin is only available for the yearly payments.
Try switching to yearly and you should now see the option.
This is odd because my first monthly payment was effectively done with bitcoin (I wanted to try it out). This was some 10 months ago. Maybe it got changed in the meanwhile.