Same here. Especially with my accountant. They're always asking me what a transaction was and if I could bring them into Missive I could easily share all of my emails labeled invoice with them without having to go track things down myself.

Echo this! We work with a lot of different project consultants, each on different teams. I just need them to be able to collaborate on a shared response, with respect to a specific project or client. I don't want to make them a part of our company. Similar to guest access: https://docs.microsoft.com/en-us/microsoftteams/guest-access

+1 awesome idea