The steps for adding or modifying your email address are as follows:
1. Login to box.com 2. Go to Account settings (click the profile pic or initials located on the upper right corner) 3. Account 4. Add a Collaborator or Link Personal Email 5. Link Personal Email > enter the new email 6. Confirm the new email 7. Go back to account settings and make the secondary email as primary and remove the original email.
I sincerely hope I have provided the support you needed. Thank you for posting!