iframe not working

Hi there, my client has this website, and on the footer the iframe doesn’t show up. I have used both code and the iframe plugin.

Using just code I write this: <iframe frameborder=”0” scrolling=”no” marginheight=”0” marginwidth=”0” src=”http://widget.mailjet.com/deb259ce1834ab3d0d0bed1b41fa4aebc83ebfbe.html” width=”250” height=”168”></iframe>

Using the iframe plugin my shortcode on the widget is this one: [iframe src=”http://widget.mailjet.com/deb259ce1834ab3d0d0bed1b41fa4aebc83ebfbe.html&#8221; width=”250″ height=”168″]

Nothing happens, what’s the problem?