You didn't really need an image for what you had before, something similar to this should work just as well:
<div style="color:#455A64;font-size: 3em;font-weight:700;max-width:100%;text-align:center;">
<a href="/">Your Forum Name</a>
</div>
Remove the text-align if you don't want it centered. If you wanted top/bottom padding you'd add: padding:10px 0px; (top/bottom left/right) or padding: 10px 0px 10px 0px; (top, right, bottom, left; clockwise).