Forwarding or Aliasing Deactivated Mail Account

Forwarding or Aliasing Deactivated Mail Account

We have an employee who has left the company, so his Zoho account is deactivated. I would like to forward any mail coming to his account to another employee, but as it is deactivated, I can't forward it. I also tried setting the same username up as an alias in the employee's account that should be receiving his email. But I can't use an alias that is a deactivated account. 

So how to do I forward/alias email from a deactivated account to another user? For now I have added a catchall account so I am getting them that way, but that is not an optimum solution. 

Thanks in advance for any suggestions! 

Ron