Question for Asian font user.

I am using in my emails (kmail) normally the default (noto I think). But recently I am getting mails from a HK provider using html mail with a story part in mandarin. While the normal writing is "beautified" easily by using e.g. AR PL Sungtil GB, the mail itself, using html, is apparently not making reference to this setting. So the letters are ugly and primitive (looking like hit into stone by some caveman) So: is there a way to influence how Kontact/Kmail renders 汉语 embedded in html with the font of my choice? And where would be that setting? Would that be "QT web engine"? Thank you in advance.