Why doesn't margin:auto center an image?
Because your image is an inline-block element. You could change it to a block-level element like this:
<img src="queuedError.jpg" style="margin:auto; width:200px;display:block" />
and it will be centered.
You need to render it as block level;
img {
display: block;
width: auto;
margin: auto;
}
Add style="text-align:center;"
try below code
<html>
<head>
<title>Test</title>
</head>
<body>
<div style="text-align:center;vertical-align:middle;">
<img src="queuedError.jpg" style="margin:auto; width:200px;" />
</div>
</body>
</html>