I recently switched over to GoDaddy email marketing and have found the editing tool to lack many options I am used to. Such as being able to upload PDF files and linking them to text in the email.
I am not familiar with HTML coding, so easier solutions are required.
You cannot upload files to an email marketing campaign, but you can definitely host the file somewhere (such as dropbox or similar) and link to it from your campaign.
GoDaddy Email Marketing