How to use different users for mailing.

How to use different users for mailing.

Hey guys,
I created a user (freddy@paintballmaskarena.com) with the same domain name (https://paintballmaskarena.com/). I want to send mails from these users, but I don't know how to access Zoho mail form this user.
I am a bit confused, Am I supposed to login from the same initial email which I used to create Zohomail? or, Am I supposed to login using freddy@paintballmaskarena.com?
Need help guys.