It doesn’t matter if your PayPal account has been created using a different e-mail address than your MonoSurveys account. You can add another e-mail address to your PayPal account. In the PayPal profile section, you can find an editable e-mail field.
In order to receive the payment to your PayPal account, you must have the same e-mail address on your MonoSurveys account and on your PayPal account.