As for the full file emails, I would try to explain that your poor old computer just can't handle them - she doesn't need to know that maybe your computer isn't so poor and old, all she needs to understand is that you don't want her to send them in the first place. As for all the email jokes and such, you can either try to politely explain that you REALLY don't want them, or just hit delete like everyone else has suggested. The joke emails are more of a nuisance than anything, but big file downloads that tie up your computer for 30 minutes at a time is just downright rude in my opinion.