New Mail Setup

Hi:

I have just validated my company domain.

I am now trying to set up email addresses.

How do I do it? I read about changing MX Address at my ISP but I am unable to find it now. Can you send me those details.

To my Zoho account, I have added an Alias.

However, when I go to my Zoho mail account the from address is xxx@zoho.com. How do I change the default to my company account?