I had a free Dropbox account for many years, using my primary email address. Several years ago, I set up a new account, with more storage, that I'm paying for so that I could share photos with my mom (now 98). At the time, I set up a new email address and associated it with that 2nd account. I don't use that email address for anything else, but now that email address has hacked. I can't log on to it anymore - they changed the phone numbers associated with it, so I can't get the log on code. So now there's a free account (that my laptop is logged onto) and a paid account (which my phone is currently logged on to). The paid one is the one I use the most since it has thousands of pictures now. I wanted to log onto the paid account on my laptop but I can't, because I can't get or change the password. I also can't find a way to change the email address associated with that account.
