Customer notification email do not contains my header image.

[SONNET Constant]

Poject settings > Customer notifications > Edit template

In html 
<div class="header">
</div>

In css
.header {
background:url("https://myPicture.png");
}

In preview html, image is visible but when recieving a notification via email image isn't.

Any idea ?

[Brant Schroeder]

@SONNET Constant   What email client are you using and is it the client or spam filter that could possibly be blocking it?