Mail messages not showing correctly catalina 10.15.2
I upgraded and updated my iMac to macOS Catalina 10,15.2, but now I cannot read/see the text in e-mails I receive (probably sent from PC). I do see the e-mails correctly on my iPhone, but on my Mac it shows a question mark or just a blank page. It does show emoticons. Also the e-mail preview shows the text correctly, but when I open the mail it just disappears.
Please see attached weird screenshot of an e-mail I received.
I tried l logging in again with my AppleID and also tried rebuilding my mailboxes; but this does not work.
Anyone any ideas?
Thank you!
iMac 27", macOS 10.15