I received an email from my cousin she says she didn't send?

Does anyone have an explanation for this. My cousin has a hotmail account and according to her she has McAfee as her firewall/virus protection etc. Today I received an email from her, it was also sent to pretty much everyone in her address book. It was an email introducing a wholesale electronics website and saying look into these prices etc. contact me to help you and so on. Anyway I clicked it and it's a website for electronics as it said. I really believed it was from my cousin as she is always into some business or another making money in different areas. Anyway when I called her, she insists that she knows nothing about this and she's been out of town for the past 2 days and hasn't even been on her computer. Now I automatically thought I was being sent some type of virus but nothing seems wrong with my computer or hers. Does anyone recognize this type of situation. Could it just be a fluke. It comes from her email adress though. Any ideas from experts would be appreciated.

I received an email from my cousin she says she didn't send?house call

If her antivirus is up to date, then someone has picked up both email addresses and sending items out as spam. It is fairly easy to send an email with someone else's address to make it look like it came from someone you know. It helps to get by spam filters that most ISPs have in place. Addresses can be picked up from messages where folks to alot of forwarding or replying to all in emails.