Proton allows only one free email address, which is what taught me to be wary of unexpected restrictions on services. I've got to say the only one I trust fully is my own, with complete certainty of security and features are all only limited by the hardware. Whenever someone talks about paying per month to get more addresses, aliases, calendar or storage - nah. Self-host. DuckDuckGo email is a good firewall layer as well - it forwards all mail to your chosen actual address after trying its best to strip the mail of trackers.