All entries in my yahoo mail address book have received bogus emails from me but the address of the emails only begins with my name and ends with some strange domain name like bookstore.com. I have two-factor authentication for my yahoo account, there are no sent emails in my account when looked at online that I did not send and no sign-ins on days and/or times that i did not sign in. How can this be possible? Basically, how can someone get my yahoo mail address book? Looking at the email headers the emails have been sent from an ISP in Canada. I live in the Netherlands. It has been going on for weeks. Any clues, solutions very welcome.