Hello,
Is your Yahoo Mail sending email From: the wrong email address?
Go to your Settings, click Accounts, and check your Default Sending Account:
If you see an account listed there that isn't one of your email addresses it's possible that your account has been compromised. Immediately change your password, verify your security Q&A, any forwarding addresses, and check out these tips for http://www.emailquestions.com/yahoo-mail/6627-prevent-your-yahoo-mail-account-being-hacked.html. I strongly recommend that all Yahoo Mail users enable the 2-step login verification listed in that guide.
Is your Yahoo Mail sending email From: the wrong email address?
Go to your Settings, click Accounts, and check your Default Sending Account:
If you see an account listed there that isn't one of your email addresses it's possible that your account has been compromised. Immediately change your password, verify your security Q&A, any forwarding addresses, and check out these tips for http://www.emailquestions.com/yahoo-mail/6627-prevent-your-yahoo-mail-account-being-hacked.html. I strongly recommend that all Yahoo Mail users enable the 2-step login verification listed in that guide.