outlook set up mail Chinese fonts garbled

I have a very irritating problem. Everyday the default Chinese fonts (including all fonts for reply emails, new emails, and forwards) that I set after clocking outlook would become garbled. Every time I reset it, the result is that the next time my computer reboots to clock outlook will revert to a garbled font again. Very irritating. The screenshot below shows the garbled fonts that appeared yesterday and today. Can you please help me to solve this problem? Thanks for your help.