Now in SageCRM, if any one wants to display tooltip on mouse over on hyperlink to view any details. It can also be customize to view image in the tooltip.
To achieve this, you only need to call function on mouse over and mouse out event on the anchor tag. We have also customized this to add any images in the tooltip. In the below screen shot as you can see on mouse over the email it will display tooltip.
Click image to enlarge it.