However, they are not three or more days old from the original posts. Not complaining or anything, just providing input in case that might help those trying to solve the problem.
One thing I noticed looking through my Yahoo.com mail account, there was a setting in the profile page that will if turned off will make your account open to who knows anyone wanting to access your email. Yahoo strongly recommends against this. And, the Yahoo instructions say some servers with older software and what they say, "outdated software" might be blocked or prohibited with connecting to the Yahoo servers. Hope this helps someone working on the problem.