I've had a Galaxy since the S3 and have never been able to sync Yahoo as it should be. GMail syncs fine, and when I set up GMail to get my Yahoo mail, that works fine. But it will not sync to the Yahoo mail on my PC. I've tried the stock email program, K9 Mail, and even the Yahoo Mail app. None have worked properly. Even my partner's AOL account will sync with his desktop, for heaven's sake, after all the bad things I have had to say about AOL mail over the years. I have tried all the suggestions in this thread...manual, defaults, etc. I can get my Yahoo mail and read it. I can even send from it on my phone. But there appears to be absolutely no way to get Yahoo mail to sync...if someone has discovered one, please correct me on this.