Because I’m an idiot, I’ve got all three of these email services sitting in front of me. Do not be like me.
Here’s the gist: HEY is nice and interesting if you like their opinions. Fastmail is ‘ol reliable. Proton is new and has maddening functionality omissions.
Let’s start with HEY.
HEY is going to ask the most of you.
I have written breathlessly about HEY’s email service before. I stand by most all of it. But I recognize it is not for everyone. There are some functionality and feature downsides:
- You are stuck with HEY’s app on every platform. It’s just a website. It’s not really an app, per se.
- Your Contacts are siloed into their Contacts, like every other platform here. Which is not at all where I want them. Like most people, Contacts live in my phone and my phone’s contacts is The Truth. This is so when I call or text people, names and numbers show up on my phone.
- HEY’s calendar is literally sideways. I don’t use it at all. I have tried and it does not work for me. If you like to time block or manage lots of events, it’s going to fail you. It’s meant for people who have 2-3 things a week, maybe a recurring block for the gym or whatever.
- If/when you export your data, it gives you a big MBOX file of everything all in one flow. This is because of how HEY treats email. It’s hard to sort/filter things into a new service beyond your Sent folder.
I still really really like HEY’s “Bubble Up if No Reply” feature to snooze an email unless someone replies, in which case, cancel that reminder. Super handy.
HEY is also going to ask you to act on messages almost immediately. You can see from my screenshot I do not like looking at all my inbox messages so I always leave it covered with their default gray checkerboard pattern (squares above in blue outline are me blocking items for privacy). This “can’t really remove things from your inbox” is part of their flow, and it drives some people mad. I’m not opposed to it.
A lot of people say HEY’s search sucks. I think all search sucks. Because the problems are usually, “I’m looking for that email from Joe … like, last year … about reports.” So you search “Joe Report” and suddenly realize your memory is bad, the search is incapable of dealing with that level of general vaguery, and people get mad. I don’t find HEY any better or worse at search than Proton or Fastmail.
HEY requires you to sort every message out of its screener into either the Inbox, Feed, or Paper Trail. This manual approach does work but requires a big lead-up time. You’re going to spend a while until you get at least one email from all your usual senders dealing with that. But it’s easy to do and the UI makes this kinda fun.
HEY’s biggest functional downsides:
- They load images for email, which is fine, and say they block trackers. I struggle to believe this process is improving. Just about any image can be used as a tracking pixel, and I don’t know how often this is updated. How do they keep up with all of them? I don’t know. Maybe they do, but I find it hard to believe it’s bulletproof.
- Their app does not lend to a lot of customization. I find managing attachments maddening since everything from photos to people’s stupid email signatures get bundled up as “attachments.”
- You can’t import your old email from anywhere.
But HEY is good about managing emails within the window. Composing emails is easy and you can “minimize” them, which is not something you can do in Fastmail. Proton has a feature for changing the size of the composer window.
Fastmail is both highly functional and very old school
Because HEY won’t let you import any email, even as a searchable archive to host it, I ended up having to pay for Fastmail and keep paying for it simply because I want to have a big hosted spot for my email. The 37 Signals guys at HEY would tell you this is a fresh start and there’s no need. Except my Fastmail inbox has random tax paperwork, threads about work projects that come up every once in a while, and even emails from people who have since died.
I have long argued HEY’s defense against switchers would be to let people import email. This way I wouldn’t be inclined to question, “Maybe I should just go back to Fastmail” every year when my $60 bill comes up.
You get labels, folders, all that. It works exactly like you think.
Fastmail’s best unique features compared to the others:
- Fastmail’s out of office reply function is best. HEY’s is incredibly dumb, replying to all sorts of random messages and receipts and automated messages. Fastmail’s is smart enough to reply to only messages sent to a specific address that are also not random newsletters.
- Fastmail lets you have 1,000 custom filters/rules. Unlike Proton which tops out at 250. More on this in a moment.
- Fastmail gives you quick access to block senders, create filters, and a host of other actions.
Fastmail shines with feature management. Want to forward the email as an attachment? Want to view the raw data? Want to block a sender? Want to create a new rule? Want to spam it? Want to mute, snooze, mute, or a bunch of other things? Fastmail can do that with it’s Actions menu.
More importantly, Fastmail carries this forward into their mobile apps. Proton has this functionality, or most of it, but you can’t do it at all in their mobile apps. I do not know why and have reported this as a bug, but was told it’s just not a feature.
This gets to what I was trying to do and why filters are important…
Can you make Proton or Fastmail behave like HEY?
All HEY does is force you to apply a filter of sorts to every sender. USPS goes to the Feed. The Bank to the Paper Trail. Jimbo to the Imbox and so on. Fastmail has rules. Proton has rules. Why can’t you just do that there?
Cause they have rule limits.
Fastmail gives you 1000, which sounds like a lot, but over the span of a year or more do you not think you’d get emails from 1000 different sender addresses? Every random receipt, every randomly generated sender address (looking at you, AT&T), every spam email.
To be clear, spam and blocked messages do not count (I am told) against your rule limits. But you can’t apply blocks or rules to messages on mobile on Proton. Proton assumes you will lovingly navigate to a special setting screen and manually type in an address or domain. This is absurd and clearly they don’t get email from the internet at Proton HQ.
Fastmail does let you quickly apply a filter (e.g., “Always send this domain to a folder called ‘Later'”), or block senders from all apps with a couple of taps. But I am worried it is not possible to sustain 1000 rules forever.
What about Sanebox + Fastmail?
I’ve written in my HEY reviews that Sanebox gets close to this function, with one huge downside: it processes after the email is received in the Inbox. This means it triggers push notifications, or, if like me you leave the window hanging around your screen, you see it pop in.
Sanebox does not work at all with Proton. But it’s barely useable for my needs in Fastmail because I see the message, then it vanishes as it gets “moved” by SaneBox to another folder. This is not how I want to work. I want to work like HEY does it where I never see or am notified of what is mostly useless fluff anyway. The inbox is for people and my work, period.
Proton Mail has some interesting ideas and better design, but isn’t ready
The best-designed of the bunch is Proton. Fastmail is not bad to look at, but the customization is maddening. For instance, you can change an accent color but not the text color (like on buttons) that goes on it. Want dark purple? Too bad, cause the text stays black.
But Proton’s exclusive features aren’t that interesting to me. You can, of course, send encrypted links to people to view encrypted messages but I won’t ever use this. And you can set messages to self destruct, which is kinda fun.
Proton’s functional limits are some of the lowest:
- Only 250 active rules (as of this writing in late 2025)
- More limits on alternative domains, which I don’t have a ton of need for anyway
- Unlike Fastmail, you can’t set folder-level rules, like, “Don’t show this folder in the sidebar if it’s empty.”
- The search has fewer knobs and whistles to play with than Fastmail. HEY has the fewest.
There are others that are well-documented, like the fact you can’t use other apps like Apple Mail or Outlook with Proton on mobile, and only on PCs or Macs through their Bridge application. I’ve not tried the Bridge application.
It is painfully obvious the mobile app struggles to connect and sync messages. You can look at the web version on your phone or any other device and see messages that do not appear in the mobile app. For an email application to randomly decide to show, hide, or just fail to sync email is a critical failure. For this reason, it seems to me Proton just is not ready for critical use.
I like the idea of bundling with Proton simply because if you already use one service, like their excellent Proton VPN, it’s not much more to use Proton Drive, Pass, and email in lieu of, say, Dropbox, 1Password, or Fastmail.
But email is very personal to people and people have finicky needs and desires. Proton meets the fewest of those and has the most bugs. Like, for instance, the fact their keyboard shortcut GI (go to Inbox) doesn’t work if you have the Grammarly extension installed and active. Others have no problem with this. Changing the Grammarly shortcut to something else, like Ctrl+Shift+J instead of its default Ctrl+Shift+G doesn’t fix it, either.
But you want to know the biggest failing of Proton?
When you have the option to show emails grouped by conversation into a thread, it shows you every email since forever. Here’s the first one I came up on in my deleted items, which shows the past four weeks. I get this email every week. Which means a year from now this will be 52 threads long. ABSURD.
You can disable this threading, but then you don’t have grouped conversations. Every other app handles this but Proton can’t. That, for me, was a complete deal breaker. That and their mobile apps aren’t at feature-parity with the web version.
As of this writing, I’m giving Fastmail a whirl again and trying to impose more filters on messages in ways that may don’t bump up against the 1000 rule limit. But I’m not optimistic. For me, HEY is still the best workflow for email I’ve used despite all its other shortcomings and stalled development.
