Kmail version: 5.3.0 /16.08.0 (was not pickable above) Qt: 5.6.1 Email on my hidpi screen only renders to a quarter of its designated space, see screenshot soon to be attached. This also happens when "opening" the email into a new window. Let me know if you need additional info. Reproducible: Always
Created attachment 100892 [details] screenshot of kmail
Same behaviour here on OpenSuse tumbleweed using kmail 5.3.0 with KDE 5.25.0 and Qt 5.6.1 My screensize 3840x2160. KMail is unusable on such displays.
I found a workaround. Launch KMail with this additional settings: > QT_SCALE_FACTOR=2 kmail See this blog post to get an idea what is happening: https://blog.qt.io/blog/2016/01/26/high-dpi-support-in-qt-5-6/ Seems to me as if KHTMLpart compnent does not behave well in some scenarios ...
I already have QT_SCREEN_SCALE_FACTORS set. Besides, setting QT_SCALE_FACTOR=2 in addition just scales the user interface again. The original problem is there nonetheless.
In addition I should mention that the mouse interactions (cursor and clicks, selections) behave as if the email text were in its correct position. So just the "drawing" is wrong.
issue persists in kmail 5.3.3. similarly, once a specific mail is opened via double click in new window, it keeps being non-scaled as seen in Lukas' screenshot.
*** This bug has been marked as a duplicate of bug 372189 ***