Here is a list of all CF7 hooks in the most current version (4.3.1):
$ grep -r do_action *
admin/includes/admin-functions.php: do_action( 'wpcf7_save_contact_form', $contact_form );
admin/edit-contact-form.php:<?php do_action( 'wpcf7_admin_notices' ); ?>
admin/edit-contact-form.php:<form method="post" action="<?php echo esc_url( add_query_arg( array( 'post' => $post_id ), menu_page_url( 'wpcf7', false ) ) ); ?>" id="wpcf7-admin-form-element"<?php do_action( 'wpcf7_post_edit_form_tag' ); ?>>
admin/edit-contact-form.php: do_action( 'wpcf7_admin_footer', $post );
admin/admin.php: do_action( 'wpcf7_admin_init' );
admin/admin.php:<?php do_action( 'wpcf7_admin_notices' ); ?>
admin/admin.php:<?php do_action( 'wpcf7_admin_notices' ); ?>
admin/admin.php:<?php do_action( 'wpcf7_admin_notices' ); ?>
includes/contact-form.php: do_action( 'wpcf7_contact_form', $this );
includes/contact-form.php: do_action( 'wpcf7_submit', $this, $result );
includes/contact-form.php: do_action( 'wpcf7_after_create', $this );
includes/contact-form.php: do_action( 'wpcf7_after_update', $this );
includes/contact-form.php: do_action( 'wpcf7_after_save', $this );
includes/controller.php: do_action( 'wpcf7_enqueue_scripts' );
includes/controller.php: do_action( 'wpcf7_enqueue_styles' );
includes/submission.php: do_action( 'wpcf7_mail_sent', $contact_form );
includes/submission.php: do_action( 'wpcf7_mail_failed', $contact_form );
includes/submission.php: do_action( 'wpcf7_before_send_mail', $contact_form );
settings.php: do_action( 'wpcf7_init' );
settings.php: do_action( 'wpcf7_upgrade', $new_ver, $old_ver );