Currently, auto forwarding conditions are limited to the subject, sender or attachment.

I've got a Duo plan and have some emails that I'd like to easily share with my partner. As the emails I'd like to share don't always fit within the above conditions, having it auto forward when put in a specific folder is the next best thing.

Proton Pass has something similar, where we can have a vault and share passwords automatically. Hoping something similar can be implemented in Mail.