Bellbram,
Don't know what email program you're using--I use N/7 in 10.2.4 and had, what I thought, was the same problem for a while. That was very disappointing cuz I really enjoyed using 'smilies', etc., in my messages. However, I discovered that when I used them in N/7, they did 'just sit there' in the message but the receiver was able to see the 'action'!!
Krissel is right... if you want to see if they work/do their thing, just open a blank browser page and drag & drop one of them onto it. If you're using N/7, you'll see its animation. Almost all of the ones I used in N/4xx work in N/7. Strange thing is, though, that they don't 'save' the same way, i.e., as gif's. They save as 'clippings' or ??? when they're dragged to the desktop. I always rename them right away so I know what they are. If you're using them in anything other than N/7, I don't know if they work the same.