Thank you for this explanation. I had already tried it and just checked all settings again. However, the problem remains with incoming mails, which are all displayed in Calibri font.
The Options > Mail > Read > Font settings (at least in my case) only apply to NewsGroup/Feed messages, not to incoming e-mails (no matter what font I change this setting to, the incoming mails keep being displayed in Calibri font).
The Options > Mail > Compose > etc settings do work though (i.e. when I set this to, say, Arial, this is the default font for composing e-mails).
Does anybody have a solution for the default font for incoming mails?
I disabled Clear Type because it causes me a headache, but Calibri is simply unbearable with Clear Type disabled, so I really need a way to change this default font.
Thank you !