How to unbind the mailbox from WeChat?

When I use this email to open the official account of WeChat WeChat, if I bind this email to WeChat, I will be prompted "This email has been occupied, please change another email", so I need to unbind WeChat from this email. There may also be some reasons to unbind WeChat from the mailbox.

1. Open WeChat, click "I" in the lower right corner of the main interface, and click "Settings".

Second, click Accounts and Security.

Third, click "More Security Settings"

4. If you need to unbind the mailbox, please click "Email Address".

5. When unbinding the mailbox, the previously bound mailbox is above the horizontal line. Click the Unbind button, and a dialog box will pop up, prompting whether the unbind is successful. If not, please check whether there is a binding between the mobile phone number and QQ number.