They represent vastly different philosophies. Fastmail is direct alternative to Gmail with good UI and UX but they're based in Australia and against message encryption as it impacts their UX (for example it's not possible to index encrypted messages). Protonmail is an OpenPGP company (they directly invest in OpenPGP.js) but have issues supporting other standards. For example IMAP/SMTP is available only through a bridge.

They’re based in Aus, but their servers are in the US (which is why I decided against switching from GMail to them in the end, and picked someone a little more local).

That means their servers cannot be directly accessed but since they're based in Australia the company can be compelled to install decryption software without notifying anyone.

Source: https://www.youtube.com/watch?v=eW-OMR-iWOE

Full text search will be coming to ProtonMail later this year (already available using the bridge).

I recommend checking out Mailbox.org or Posteo as well. They are much cheaper, and Mailbox.org allows for custom domains, so that's a definite plus.

I've used both for some time and decided to move to Fastmail and so far I am very satisfied.

Fastmail does one thing and does it well, email. There is no PGP support. Protonmail does PGP in the browser via a library that they serve you themselves which I find less than ideal. If you want to do it outside the browser you need to have a subscription and download a bridge software that needs to be running on your machine. With Fastmail if I need PGP in my email I do it via the GPGTools plugin for the Mail app which uses the system gpg installation.

I use both. Fastmail is more compatible with clients and has a good per-client security model. However it is based in Australia, which has increasingly insane digital privacy laws.

Proton mail has more advanced cryptographic features and my understanding is that your email is encrypted so they can't offer it up to third parties without your consent (or at least stealing your password.) The usability is not as good: search often does not work very well (I believe this is due to the encrypted nature of it) and there are only a handful of local clients you can use via their bridge. The mobile app is pretty good, the web app is acceptable but clunky.

I use fastmail for day to day stuff I don't care too much about and protonmail for my more important/personal stuff. Both support custom domains so you can move your email to another provider if you get sick of one.

Are entire emails encrypted, or is the metadata in the clear?

(Ex: I could search by the [Mailing-List-Tag] + date range, from address etc)

From the search results I get, the body appears to be encrypted but things like sender/subject/etc. are in the clear and can be indexed.

This is why I hope they fix the bridge: I'd like to index my email fully and locally, but I'm not going to use thunderbird to do it.

I use both.

FastMail:

+ simple, lean, paid email.

+ fast web interface

++ working full text search( not just subject line)

+ No ads.

+ iOS App. Fast and simple.

+ Integrated calendar

- No encryption.

- group calendar has been a pain or non intuitive.

Protonmail:

+ Encrypted

+ Lean, safe web interface

+ IOS App that works.

+ or - Free as in cost.

- - - No Full text search.

- can't really configure your chosen email client to it...

- last time I tried, dragged and dropped images disappeared. May have improved UI now.

I only use protonmail for automated alerts and system originated communication.

About this point: "- can't really configure your chosen email client to it..."

Do you have any experience with using the IMAP Bridge? It is a daemon you run locally that translates between Protonmail's internal protocol and IMAP, to let you use your email client of choice. I'm using it and it seems to be working OK in my experience, but I don't use my Protonmail account heavily.

My experience with the bridge (on an account with maybe 10k emails) was that it was unfortunately unusable.

Did you try the bridge recently? The last update should have fixed this issue for large accounts.

Thanks, I tried the latest version just now and it synchronised all folders without crashing (never happened before for me).

Fastmail is a great host and I liked their iOS app. ProtonMail seems like a good idea but promising secure email and secrecy as an mail provider isn’t really realistic at all.

I use both, and both are good. Fastmail does calendars and notes. Both have roughly equivalent keyboard shortcuts in the web apps.