Very few legitimate companies will sell lists of raw email addresses, to anyone. There's very little money in it (email lists are cheap) and the potential upsid

Very few legitimate companies will sell lists of raw email addresses, to anyone. There's very little money in it (email lists are cheap) and the potential upside of keeping the email addresses is way bigger, particularly when your email address is married up with behavioral data like what you bought, what pages you visited, what bank you use, etc. Retailers make money from your email address by trying to use it to get you to spend more money with them. That can be as simple as sending you marketing emails--which many people consider spam! So when you hear people complain about "spam" from retailers, it's often this: real marketing emails that they are mad about getting. Companies can also use customer email addresses as tokens for targeting in ad networks. In doing so, they may upload your email address to the ad platform. In that case they are sharing it with another company, but it won't result in spam. It will result in greater correlation between the otherwise separate tracking of your behavior across companies. In this case, using company-specific email addresses may actually be an advantage in terms of foiling such correlation.