all emails with asian text received from others becames garbage chars

Since the webmail of usermin is not utf-8 capable, I installed other webmail client squirrelmail which is fully support utf-8.

I send email with asian text from squirrelmail, the recipient could read the text properly. Where
emails received from other ppl are all garbage chars shows as below link

It looks like there’s an update to this support request regarding that issue here: