Thousands. I had a scam done to my email a few years back. They hacked my Amazon account and tried to buy some things, at the same time they used some scam service to sign my email up for thousands of websites so that my email would be flooded and that I would hopefully not see the Amazon purchase confirmations. In one day I was getting tens of thousands of emails. I considered giving up the email address entirely, but over a few days I was able to mark all the messages as "spam" and now that is where they go. At this point I receive a few spam emails in my main inbox, but the rest go to the spam folder.