For DotNetPanel Account
For the new sign-up account, when it is activated by default the main domain will have one account mail@domain.com with control panel's password.
You can create another new mail account from your DotNetPanel or reset the existing mail account password.
Please refer to this article to create new account or reset current account password.
For old In House Control Panel Account
By default, when you create a new domain from control panel , your email account for that particular domain is setup automatically.
You can login to http://mail.domain.com.
and login as postmaster@domain.com
and with password : your control panel's password.
Login as postmaster is the default admin account for your domain email.
You can create user,delete , change password, modify spam filtering and etc.
