Filter the email where a submitted feedback is sent.
contact_form_to
contact_form_to-
filter -
filter contact_form_is_spam_akismetFilter the results returned by Akismet for each submitted contact form.
-
filter grunion_contact_form_form_actionFilter the contact form action URL.
-
filter jetpack_contact_form_is_spamFilter whether the submitted feedback is considered as spam.
-
filter grunion_optimize_tableFilter if the module run OPTIMIZE TABLE on the core WP tables.
-
filter jetpack_auto_fill_logged_in_userAllow third-party tools to prefill the contact form with the user’s details when they’re logged in.
Jetpack Developer Resources 