BillC

Is there any way to stop someone form using my e-mail to send out spam? My mailbox is getting more and more "Undeliverable mail" from different servers. Also I don't want anyone getting mad at me for Spam I'm not sending. I'd still like to use my e-mail but not sure how to block other people from using it. Any ideas? I changed my PW in Cpanel, but I'm still getting returned mail.