I created a custom maintenance page which appears after setting the maintenance.flag file.

The custom page has a few forms which I copied from the normal page, but they are not working. Validation and date time picking works but If I send the form then I get 503 service unavailable in the network analysis.

I need the forms so that users can contact me and order stuff while the page is down.

It works without problems on the main page if the maintenance.flag is not set? How can I allow the form on maintenance mode?