Give Missive an overview of your company, people's roles, etc (or provide some data source where this can be queried live). Send this roles/responsibilities/routing decision information to Jev, with a list of possible teams and users to assign in Missive. Let Jev assign them, falling back to some specified team on low confidence matches.

This can, of course, be built as a separate integration. Which I will do in the meantime.