How to link old folders with my changed email id

Hi Prashant, 

Welcome to the Box Community!

If you need to change the primary email address linked to your Box account, you may follow the steps provided in this article:

• https://support.box.com/hc/en-us/articles/360044196513-Manage-Account-Settings#loginandemail

Thanks for reaching out and please let us know how else we can help!