Cypht has become Tiki's webmail:
https://doc.tiki.org/Cypht
Why Tiki picked Cypht over the more popular Roundcube:
https://doc.tiki.org/Roundcube-vs-Cypht
Cypht within Tiki has many even more advanced features:
https://doc.tiki.org/Email-filters
https://doc.tiki.org/Calendar-Invitations-by-email
https://doc.tiki.org/Email-folders-Tracker-Field
Many more developments are planned for Cypht version 3.0:
https://github.com/cypht-org/cypht/milestone/4
This is further in the future, but I would like the system to learn from my manual operations, and propose things: https://doc.tiki.org/Machine-Learning
I urge you to join us!