Calendar Stickers for Outlook

I want to make a small Outlook add-in that lets you mark a few days on a calendar and drop it into an email like a sticker. The point is to keep the visual attached to the conversation, with just enough configuration to make it useful.

The proposed next step is for recipients, including people copied on the email, to open it and choose a time. This is a concept so far: the add-in, calendar integration, and scheduling flow haven’t been built or verified.