Are there email clients that group emails by sender in the same way that messaging clients do? I realized recently that an email client structured in this way c

Are there email clients that group emails by sender in the same way that messaging clients do? I realized recently that an email client structured in this way could encourage long-form messaging similar to what Pony aims to do, though such an email client would still lack the once-a-day dynamic. Alternatively, Pony could maybe piggyback on email by providing an email address that proxies to each Pony account.