Still useful even if it's old school.
Web based:
- Gmail
- Protonmail
- Fastmail
Text based:
- Mutt
Emacs based:
The decline of email
Email isn't used as much nowadays (2024) given that most people will communicate via chat applications (WhatsApp, Signal) or social networking apps (Twitter). Or via chat apps from social networks (Facebook Messanger). Or even simple cell phone texting.
Still, email is good for people who don't have social media.