If you wish to change the destination email of the contact form in your contact page, go to “Contact Forms” in the “Contact” menu. It will open the list of all your forms.
Find your main contact form and click on it to open it. Go under the “Mail” tab and the first field you see is the one you want to change. Enter your new address and click “Save”.
Note: For more informations about how do edit the contact form itself or build new forms, please refer to the “Contact Form 7” plugin documentation accessible here.