Another reason to keep them separate is that it reduces cognitive noise when dealing with spam. I use separate addresses for banks, brokerage, etc. Because the

Another reason to keep them separate is that it reduces cognitive noise when dealing with spam. I use separate addresses for banks, brokerage, etc. Because the email address associated with each isn't used elsewhere, I can almost always identify the culprit when it starts getting spammed, so I can cease business with and blacklist anyone who does it[1]. Because of that, any phishing attempts that go to the wrong address, even well done, tricky ones, are so obvious a machine can trash them with certainty. Yet another reason is that if someone is going to try to guess/steal your password, if they don't know the email address used for that account, that's something else that can slow them down/trip them up. [1] That is how Wells Fargo lost my business, well before they made a surprisingly strong go at proving Lenin right about capitalists.