The AliExpress email shows that it has been registered, which means that you may have registered other websites with the same email or name at some time. The most likely possibility is that the name you used at that time has been used by someone else when you register the email. Therefore, when registering an email, you may have to modify the name once or several times before you can register successfully.

If the above prompt appears when you register, it means that the email has been registered and used before, and the system automatically reminds you.

The recommended solution is:

Please change the email address that has not been registered and click on the free registration again.