1 - If you are speaking about css and images of the email content that's of course normal if you dont use absolute URLs, images must be like : http://www.site.com/img/banner.jpg and not like the site pages where you can use relative URLs like /img/banner.jpg.
2 - The link that you are using contain an error, I dont know if this is an example or you'v copied it from your real site (Im speaking about params of course : mode=activateusername=user&activationcode=D56gsjd ), the error is after mode=activate you should add an '&', so the link must be like this :
site.com, is somebody else's url, Do Not post faked urls they always turn out to belong to somebody, and DaniWeb will get blamed for your being ignorant of the social niceties.
Use your url, and/or post the code that the screwup applies to, then help will be more likely to work, since those who care enough to try and unravel the screwup will view source to find your css
root = tkinter.Tk()
buttons=[i for i in range(10)]
#If specific button is pressed, output "YES"
for num in buttons: