Yahoo Mail on iphone problem

Question

I do have yahoo mail on my iphone for a while and it was working perfect.
Few days ago I got:
Cannot Get Mail The user name or password for "[email protected]" is incorrect.
I do not have any problem when I login from my PC with same User name and password.
When I try to set up my email from I phone again. Here is what I got:
Cannot Get Mail The user name or password for “imap.apple.mail.yahoo.com” is incorrect.
I can make all my friends’ yahoo mail work on my I phone but only the one mail account used to be working fine does not working now.
Can someone help me?

Answer 1

I've had Yahoo Mail Plus for over 5 years without any problems (Yahoo Mail "Plus" means you pay $20/yr to get POP mail access using a standard mail clients). But since I got my iPhone 3GS, I've been having frequent problems accessing Yahoo Mail from my Mac Mail client, via web browser, etc.. My iPhone replaced a Treo 700p, and I used to have no problems, even with two Mac Mail clients and the Treo accessing my POP mail every 5 minutes. Now, since my frequent problems started, I've cut way back on the POP access on all my mail clients (which Yahoo Support told me to do), but the problem persists.
QUESTION: Do you guys with problems have the standard (free) Yahoo Mail, or Mail Plus with POP access?
THEORY: When I got my new 3GS, it automatically imported the mail settings from my Mac Mail client. However, instead of keeping my POP settings for Yahoo Mail, it changed the setting to the Push/IMAP for my iPhone. The Push settings would be great for most people, but not so much for people with Mail Plus who access mail with POP settings. The problem is, when an email client accesses POP mail, it tells the IMAP mail client that all email has been read (when it's simply been downloaded). I think Apple should not, by default, import Yahoo Mail settings which are set to POP, and then change the settings to IMAP on the iPhone -- at least ask the user before making this change. Anyway, my uneducated theory is that the simultaneous IMAP and POP access to my Yahoo Mail Plus account screwed something up, and now I keep having problems accessing mail. I've since deleted the default Push Yahoo Mail account from my iPhone, and set it up from scratch as a POP account. But my mail problems persist.
Also note that, a detailed debug message I get sometimes (usually with error code 5, though once with error code 20) always list the same date/time, which is really close to when I got my iPhone, and also when my problems started. In my mind, that supports my theory. I've been waiting for Yahoo Support to address this detailed debug report, but they keep on giving vague responses (basically telling me over and over that my issues are due to accessing my mail too frequently).
Here's the error code details I've received when trying to access my Yahoo Mail via web browser (note the date in line 3):
Error #5:
0: ListMessagesFromIds
1: SOAP-ENV:Server.MailboxOpenFailed.Busy
2: Error opening mailbox: mailbox busy
3: V2.1.0 B1357.22 06/18/2009 07:28 AM
4: cg1.c701.mail.mud.yahoo.com