Multiple contacts in one opportunity

What does “…tag other contacts… INSIDE of the opportunity.” mean to you. Physically, this isn’t possible per say but maybe I’m not understanding your reference.

My goal is to get the emails from 2 or 3 different contacts to all integrate in the recent email history at the bottom of the opportunity page to follow all of the correspondence. 20% of all of our orders involve more than 1 contact.

So unless you plan on manually managing the opp records by hand, it won’t be automatable with the existing tools out there then. It can be done (as I’ve noted above) a couple of different ways with a custom code solution.

Is Macanta the custom code solution? Does Plan B Provide this service?

I don’t really know what Macanta can do in this area but it doesn’t sound like anything I’ve seen mentioned in regards to them. Custom code refers to an integrations developer creating a custom solution, which, yes, we do create custom solutions like this for clients.