in my projects I am using a custom settings page for having sme contact data in one place (created with Metabox.io).
Now I want to use the e-mail field from this settings page as default form recipient.
I would like to eighter override #blog_admin_email or to introduce a new custom variable for example #settings_site_email.
$email_to is an array of email addresses. You could use the wsf_action_email_to filter to change the recipient email address from the admin email address.