I am unable to send emails from my personal account. I have tried sending new and forwarding old emails to my Yahoo business account numerous times day, and have yet to receive one. I can send and receive from the business account.
If you send email from your personal account to a test account that isn't yahoo, for example sending to a Gmail account, are you able to receive the email?
Check the filters and spam folder on the business account to make sure the emails are not being blocked.