Html report is not rendered in outlook mail body

Question

Hello, I'm creating pytest result report using pytest <mytest>.py -vs --html=<path_to>/emailable-report.html --self-contained-html, and automated it through jenkins. I'm sending the mail body using body: readFile(<path_to>/emailable-report.html), but I can't see it like this from the mail body. At the same time, I can open this same report file from browser (edge, chrome, etc). So this html is not rendered well only to outlook mail body. I tried to change my code, or I also ran System.setProperty("hudson.model.DirectoryBrowserSupport.CSP", "") from jenkins as recommended, but nothing worked.