I recommend ProtonMail.
Or you can buy your own domain name and config a email to Zoho Mail.
but personally, I think proton mail is more secure and private. But the free version only has 1GB as I remember.
ProtonMail is an interesting case. It does not provide SMTP or IMAP servers, except via a weird proxy service that runs on your local machine, and obviously isn't compatible with smartphones.
It may still class as an "email service", but only just, since it is effectively limited to webmail and their custom apps.
+1 to ProtonMail. I've been using it for several years and was recently grandfathered into their Proton Unlimited plan that allows for additional domains, extra storage, etc. They have had technical issues a couple of times since I started using them, but support was always responsive and it's been overall a nice experience mail-wise.
In terms of their other products, I think they have quite a bit to go with Proton Drive (no widely available Android app is preventing me from switching from Google Drive) and Proton Calendar (unable to import large calendars, won't let you just import future events and ignore past entries to decrease space requirements).
It may still class as an "email service", but only just, since it is effectively limited to webmail and their custom apps.