Replies are sent from the wrong address when the incoming email to/cc list was not visible
When there is more than one yahoo address to send from (Addr1, Addr1), yahoo will use a default to send (I believe Addr1). When replying to a message that was set to Addr1 or Addr2, yahoo will use the correct address when replying. However, when an email is sent to Addr2 and Addr2 is not included on the to/cc line (e.g. email blast, BCC, etc.). yahoo uses Addr1 to reply. This is incorrect, and instead it should use the address it was actually sent to, not use Addr1 by default because it was not explicitly called out as a recipient.