Unfortunately, you can't - your email address is your identity. You can't really have an "anonymous" account with the same email as your registered account. You also run a very real risk of having your accounts merged by an employee trying to be helpful, since the 99% scenario here is that people create unregistered accounts by accident.
Unregistered accounts are also not designed to be "logged in" to. You retain access to them for as long as you have the user cookie, but if you lose it, we'll ask you to register on account recovery.
Let's try this: I changed your email on that unregistered profile by appending
+12345 to the email. (So, if, say, your email was
firstname.lastname@example.org, it will be
email@example.com.) This won't change your ability to receive email, but it will make it possible to do account recovery on that account alone. Here's what you should do:
- Open up an incognito/private window in your favorite browser.
- Go to https://workplace.stackexchange.com/users/account-recovery
- Type in your new email (with +12345 in it). That should send you an account recovery email.
- Open the email in that same browser window and click the recovery link. Set a password. You won't be unregistered at that point, but you will have an account that's separate from your main one (at least in theory).
If you hit any snags, drop me an email privately (address is in my profile) and I'll see what else we can do.