Both the Win16 and Win32 variants of IE4 can display UTF-8 characters on webpages.
Sadly, IE4 - and the so-called IE5 - for Windows 3.1x and NT 3.51 CANNOT send UTF-8 strings.
Worse, even if there is no accented character, you may get blank page while attempting to post.
Therefore, even sending a message fully written in English (ASCII characters) may cause trouble.
I gave up to solve that infamous issue a long time ago... AFAIK, all Win16 browsers are affected.
On Windows 95 or NT 4.0, you get the UTF-8 issue with IE3 or older but IE4+ completely fixed it.