How to create a backup email address in SmarterMail
Visit your SmarterMail webmail control panel > Settings (Gear icon on left navigation bar) > My Settings > Accounts Settings > Enter Backup Email Address > Save button
Backup Email Address - The email address to which password reset instructions will be sent if the user forgets their password. Generally, this email address will need to be separate from this account - possibly a GMail or Yahoo! email address, or even the default email address of a domain administrator.