I actually just began the process of migrating away from Google about two weeks ago. I chose FastMail for my new email provider. It's $5/mo, but honestly, I'm fine paying that, solely to get Google out of my emails.
I find their UI to be simple and clear. I enjoy the notes/calendar features that come with the email. Their mobile app works fine on my android phone, and the push notifications from the Fastmail calendar are relatively unobtrusive.
Only downside so far was I had to cancel my NYTimes sub (honestly probably a plus) because it doesn't recognize the @fastmail.com domain as a valid email address. It's the only service I've had that problem with, including the important ones like banking, etc.
Huh, I didn't know about that. I knew I could use my own domainl; but I'm not really motivated to do so. the fastmail domain suits me well enough. I always have the option to use my own domain later on, anyway.
My NYTimes sub goes to my gmail, and then it forwards to my fastmail (I rarely need to check my gmail).
I was unable to sign up for an Etsy account with Fastmail. They only acknowledge the majors. But I was able to sign up with gmail and then promptly change it to fastmail. Really sophisticated opsec on their part.
I used to not like Outlook at work, but when I worked for a startup they used GSuites and the Google mail experience is so bad I honestly couldn't believe that anyone would be using it. Threads are mixed together when multiple people reply its impossible to read content anymore and they do also change the formatting of content which puzzled me the most.
Maybe for people that only ever used Gmail it's okay, because they are used to its weirdness and have never seen a more structured and visually appealing way to read email.
I just changed from a job that used GSuite to one that uses Office 365. I think Outlook is total garbage. The desktop client especially, and the website is barely an improvement. I've gotten used to it in the last month, but I still think the threading UX (my main gripe at this point) is really poor.
Maybe the lesson here is that if you use one of them for years, then the other seems really bad.
Outlook for Desktop has its quirks, but it's still extremely usable and (mostly) performant, especially compared to any of the web-based mail clients out there.
I don't know about the client, but make sure you are paying for the email SERVICE with your money. You want them to think of providing good service as how they make money, not scraping your email for advertising (or ??? - I can make up conspiracy theories...)
