Hi cdelvaux65,
I need more clarity on the taskbar that you're referring to. Is it the system taskbar or the one on browser? You may not be able to add the print option in the system taskbar. However, if it is missing from the browser (Internet Explorer), it can be added. Will let you know the steps, once you confirm the details.
From the information that you've mentioned, it appears that you are trying to print an Email attachment. To do so, you need to open the attachment and then give a print command. I may have misunderstood the requirement. If so, please elaborate the situation again. Will take it forward.