Get rid of "underline" hyperlink on icon images in email signature?

Hi all,

I have just created a swanky new email signature for my business email account in Apple Mail and I am having some issues.

I have inserted 3 social media icon images for Facebook, twitter and Instagram and Linkedin and linked them to the corresponding accounts. However, as Apple Mail recognises these now as links it creates a line underneath/beside the icons. I am assuming this is because they are essentially "hyperlinks" but it just does not look good!

Does anybody have any ideas on how to get rid of the annoying lines? I have attached an image to give a clearer idea of what I mean.

Thanks