If someone unsubscribes from an email they received, say from company A who uses constant contact as an email platform, does this also unsubscribe them from emails sent from company B who also sends out emails using constant contact?
Great question! It will not. Constant Contact is just the platform. If someone unsubscribes from one account's mailings, it will not unsubscribe them from another. It is possible for them to request to be blocked from receiving anything sent from Constant Contact if they so choose, but they would have to contact Constant Contact directly.