You can create email aliases (or redirected email accounts) up to the maximum allowable in your plan.
In Smart Mail Admin you can add email aliases up to your plan's maximum. There is no space allocation for an email alias as there is no actual account.
Log in to Smart Mail Admin and navigate to My Email Aliases
Your alias has been saved.
You should check to make sure any emails sent to the alias address get redirected to the address you recorded as the target address
If you send emails from the targeted address with the from address as the alias, make sure you have the ip address of your targeted address as a qualified ip in the dns spf record