The whale𝗖𝘆𝗽𝗵𝘁:
https://thewhale.cc/posts/cypht
Cypht is a simple, lightweight, and modern webmail client that aggregates several accounts into a single view. Cypht (pronounced "sift") is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into one. And it's also a news rss reader.
