how to delete secondary email

Hello,

How do I delete Secondary Email of Administrator? I have used abc@xyz.com while Primary Administrator while setting up Zoho Mail.. And Now I have made other email abc1@xyz.com as Primary address. So previous email address abc@xyz.com is showing as Secondary Email address. I am not able to Delete that..

I want to delete that and add as "Alias" to other email address.

How can I do that?

Thanks,