[Forums] background-image & mails

I created a little webscreen (MailProblem/Screen Flows/MainFlow/TheWebscreen) with a button that sends an email (MailProblem/Screen Flows/Emails/TheMail).

In this mail I used some CSS (

.DivWithBackground {width: 200px;height: 200px;background-image: url(http://www.space.com/images/i/000/005/972/i02/sun-photo-solar-filament-101118-02.jpg);background-size: 100%;}

to create a div with a background (refering to a public image at http://www.space.com/images/i/000/005/972/i02/sun-photo-solar-filament-101118-02.jpg )

But when I receive the mail... there is no image...

:-(