Everything should work now 🙂 Just delete your existing yahoo setting and redo it again. Smooth as baby's bottom! (until yahoo screw up again that is lol)
I had recently just purchased a brand new iphone 3Gs from an AT&T store here and signed up with a plan. So yesterday I was a totally new customer, and having this issue with my NEW phone. I got the gmail working the first time I tried it, and tried numerous different suggestions on here as to chaning the "ingoing" and "outgoing" servers...setting it up as an "other" email account. I tried waiting overnight (last night) to see if it would just start working. Nothing. Not any of those worked at all, and it was really starting to make me angry cause I just paid all this money for this phone, and I can't even get a part of it to work, a part that I actually bought the phone for.
So, having said all that...
THIS is what I did, that FINALLY got it working, I know it has been posted on here many times before, and I didn't believe it would help, but...
I simply changed my Yahoo! password. The only thing different now is that it doesn't have a special character in it. That is it. The next time I tried to do it, bam...I got the check mark that said it was good, and it is indeed working now.
I hope this helps, I know how frustrating it can be.
I had the same problem. Stopped working and I had more then 350 messages on the server. So what I did, a cleaned up the inbox and now it is working fine. Maybe one can try to just keep the most important once, or put them in a different folder rather then inbox.
Also to say the password change or the yahoo site change from US to UK did not work either and I never had special characters in the password.
The iphone mail likes passwords with alphanumeric characters. Make sure you have no other characters but letters and numbers in your password. This restored my yahoo mail on my iphone after it refused to accept a password with a non alphanumeric character.
