changing default email in account settings for individual account

Hi there, 

Welcome to Box Community and glad to assist! 

You could change your email address by adding it first as your secondary email then switch it as your primary email. 

To add an email address:

1. Click Add More Emails.
2. Enter a valid email address.
3. Click Save.

An email verification will be sent to the address you entered. Click the verification link in the email to confirm and add the alternate email to you account.

• Click Make Primary next to the email address you want as your primary email address.

Hope it helps!