+1 for Zoho. I use their completely free service for all my custom domains and I find the webmail pretty good. The web applications, in general, are pretty act

+1 for Zoho. I use their completely free service for all my custom domains and I find the webmail pretty good. The web applications, in general, are pretty actively maintained, with new features every few months. Only had one bigger issue over the years and they resolved it within 24 hours. They also have a native dark theme on webmail that is pretty decent.