If you are hosting your e-mail with us you can easily setup new email accounts or aliases.
Generally speaking you should set up one email account per real person, and then use aliases for generic terms for example sales@mydomain.com. An alias is an email address that receives emails and redirects it to a full email account.
When your domain was set up on llocally you should have received an email containing your master account name and password.
Follow the instructions..