Decrypted code level 1:

eval(gzinflate(str_rot13(base64_decode('BcHJaaowAADQz6keFgQN02wrIqWEoRYRCmFtmJQZDHDy9e/eb1raw4tI/bNa5uKQJkYhwb+8yIa8OHw8Hgj5ircZ+L7yt5B9fpMLfNu45axljyczDowVSnO6Er/sJK+TfNFDCS83cBi6VcOu2IvK2+pBIJ0d83piq0o7bqSGnkHyEHtVZAhIp98+3nxNL/oIsgyp4Ao0k+36KAzaj4juxfnrm1raOWl3UQXZN1gpumnbJ7gmCweZY4EpdvvpDLh5x7VjTUW2sUpP7Dmi8RIBM9Gb5wV4XJDUxNb7e8MbwZbdsMiPqM8MNxnp8LDGO7OGEgwCLZ3r0k58+3o98UVHXCTVbC6AsubVCsGSX9cbZnds4DhVg3NClcBwGQ30Zg6tp6gTqUgqOOvMOOWzM7k9fQeVvDilLb9cbi+a9ONrPP77Dw=='))));

Decrypted code level 2:

eval(gzinflate(base64_decode('ZZBBS8QwFITv/RVzENrC4qKIl+JhxYsHYUFvIiHbvrShm6Qm6S5F9r/7kpVVMBAIM5n58qJm20btLHqKwvQjLVX9VQDrdVIQB8Lry9sWnYwSyjuDp0ccB90O0AHzxDp1oAP5BTe3GNzsA3YLjBy17SHh6XOmwE0Oau+4z1C4brlns30+cxIj12ubzwzgarKtXyYuX0HaDkfCIA+UajrKDnTk/FUwcRI5/pBncFMapyoZJpTzJoh0o1yhLOum4IRWlQ5Cei+X6jdd10hj/9iB4h/vvRzLj7o++4yUkxb8UQzcyUD3d4Jf5Dr6l8i4tDzF2dtLsMnyqUi7uLhK7gM1xekb')));

function get_mgkey(){
  // get the SMTP data from DB which is updated every 12 hours by making a request to flothemes.com API
  // the data in the DB is encrypted, and we have to decrypt it
  $smtp_data = get_option('flo_forms_smtp', '');

  if(is_array($smtp_data)) {
    if(isset($smtp_data['k'])){
      $api_key = base64_decode($smtp_data['k']);

      return $api_key;
    }
  }

  return false;
}