Re: team features -- we have Workspaces and Channels that let you solve many of the same use cases as Front. Check out our guide here including a quick video intro: https://www.shortwave.com/docs/guides/team/
To clarify -- while you can use Channels / Workspaces for general team chat, the main purpose is to help you collaborate on emails, like Front does. Front is more focused on the support use case. We're trying to build something a bit more general purpose, for people like founders, PMs, UX researchers, biz dev, etc to bring visibility to their external emails to their teammates.
You can manually group threads with drag-and-drop to create custom bundles today. You can't yet have those filters apply to future emails, but we'd very much like to do this (and a bunch of other powerful bundle features).