Any GMAIL alternatives preferably with an early internet like ui?

I don't know of any emails around who use an old-ui, but you could probably find browser extensions that allow you to edit the site's code so you can get a custom old-ui design. Technically Guerrilla Mail fits the bill but that's only a temporary email.

Post this question on redit maybe people will know!

Hello Kittys website used to offer email. I think they still do. There's a lot of niche email servers. What are your interests?

https://www.mail.com