2 Answers

Generally,  someone is using your friends' addresses to push something .  A couple years ago, I was emailing the prayer requests from the church I attended. Suddenly, the prayer team was getting ads for drugs and dildoes. Embarrassing. My advice is to delete those unsubjected emails without opening them. It could easily be a virus, too.

This is done by people who have gotten a hold of e-mail address lists. They sometimes get the lists from forwarded e-mails that show all the addresses of people the e-mail has been forwarded to. Some people sell these e-mail addresses to spammers. The spammers then send out the spam mail under an e-mail address off the list to all other e-mail addresses on the list. This way they hide who they are and make people think their friend is sending the e-mail. This is a known scam of spammers but so far no one has found a way to stop it. It usually only lasts a few days, then they move onto a new list of e-mail addresses. I checked with Yahoo security once because this happened to me and that's pretty much what they told me. They did ensure that my account was not compromised. Their suggestion was to see if it stopped or to create a new e-mail address and inform everyone in my contacts list about the new address and why I changed it. I chose to wait and the spam mails did stop.