Deactivate “Yahoo! Mail for iPhone” to allow the Palm Prē to access Yahoo!…

My solution for the common errors  “Invalid security token: 4 1213 0” and “Invalid security token: 6 1236 0” was to deactivate the “Yahoo! Mail for iPhone” partner application at Yahoo! before attempting to add my Yahoo! email address to the Palm Prē.  These steps resolved the problem:

  1. Sign in to your My Yahoo! account profile and then access the “Account Info” page.
  2. From the Account Info page, click on “Link your account with other sites” (in the Sign-In and Security section).
  3. On the resulting “Account Sign-In Settings” page, enable the check box next to “Yahoo! Mail for iPhone” and click the “Continue” button to deactivate that application.
    1. After the webOS 1.3.5 upgrade in Dec ’09, I also had to deactivate “Palm Synergy”, “Yahoo! Mail for Sprint/Palm” and “Y! Messenger Authentication” to resolve the constant “Please re-enter your password” errors on the Pre.
  4. Sign Out of Yahoo!.
  5. Restart the Palm Prē; follow the regular instructions to add your Yahoo! email address to the Prē.

Once those steps were done, the Account Sign-In Settings page showed a new Partner Account called “Yahoo! Mail for Sprint/Palm”.   The problem turned out to be (apparently) a conflict with the “Yahoo! Mail for iPhone” partner application link that was created long ago when I configured my iPhone to access Yahoo! Mail.  Hope this helped.  By the way, the manual configuration steps suggested on Yahoo! Answers did not work for my Prē ( ).