There are many free/freemium webservices that send an e-mail notification whenever the content of a certain web page changes; e.g., visualping.io, changedetection.com, onwebchange...
Unfortunately the page I wish to track is the result of a search which is sent using a form via POST. It is a pure search without side effects, so I think that GET should have been used in this case, but it is an external website and I am stuck with it.
Is there a free webservice that can monitor the result of a POST query and send me an e-mail upon changes? Or a software/script that I can host myself? Linux is preferred, in this case.