gravity_form_list_notification_from_adresses.php

<?php
    $username = "";
    $password = "";
    $database = "";
    $table_prefix = "wp_";

    $blogs_prefixes = array();

    $db = new mysqli('localhost', $username, $password, $database);

    $query = "SELECT blog_id, domain FROM {$table_prefix}blogs";

    $resource = $db->query($query);

    if($resource)
    {
        while($row = $resource->fetch_array(MYSQLI_ASSOC))
        {
            $blogs_prefixes[$row['domain']] = "{$table_prefix}{$row['blog_id']}_";
        }

        $resource->free();
    }

    if(!$blogs_prefixes)
    {
        $blogs_prefixes["localhost"] = $table_prefix;
    }

    foreach($blogs_prefixes as $blog_domain => $blog_prefix)
    {
        $query = "SELECT notifications, form_id, title FROM {$blog_prefix}rg_form_meta INNER JOIN {$blog_prefix}rg_form ON ({$blog_prefix}rg_form.id = {$blog_prefix}rg_form_meta.form_id) WHERE is_trash = 0";

        $resource = $db->query($query);

        while($row = $resource->fetch_array(MYSQLI_ASSOC))
        {
            $data = json_decode($row['notifications']);

            foreach($data as $notification_key => $notification_data)
            {
                $email = $notification_data->from;

                // Do some tests on $email, is it a static email address, "{admin_email}" or "{field_name:field_number}"

                echo "{$email}\tin notification '{$notification_data->name}'\tin form {$row['form_id']}\tnamed '{$row['title']}' at site '{$blog_domain}' [{$blog_prefix}]\n";
            }
        }

        $resource->free();
    }