how simple can I get

I had a customer who was getting repeat e-mails. I did the normal thing and checked her mailbox. I found a 6MB e-mail and she has dialup. I tried explaining the problem as simple as I could. I said "The mail gets stuck on the big message and starts over at the beginning". She didn't understand. I questioned, "Do you understand that it is stuck?" She understood that, but she said she didn't understand that it was starting over at the beginning. How could you explain that in a simpler way? Is starting over technical language? I guess it is too much to expect anyone to use common sense!