Email passwords being rejected in Apple Mail etc

iCloud is not compatible w/SL.

I installed iCloud on the iPad

K, that wasn't clear in your original posting. You left that part out.

Are you saying this would be fixed if I upgraded to Mountain Lion?

That is not what I said. What I should have said is that the OS requirements for iCloud are Lion & Mountain Lion.

The following are keychain troubleshooting that you may wish to try:

Use Spotlight to search for a file called login.keychain.

Users/YourUserName/Library(which is a hidden folder and won't show in Finder)/Keychains.

Click Go in the menu bar then Go to Folder and type in /Users/YourUserName/Library and hit the enter key. Look down the list of folder and find Keychains. The "login.keychain" file should be inside.

Cures for a funky keychain

I have this happen randomly all of the time with the domain at my job and my email at the domain at the school where I do network management. Doesn't happen to any one person frequently, but mail suddenly stops and then just as suddenly starts working. Yesterday my iPhone shut me out of the school mail, this morning it was healed -- I could get the school mail on my laptop just fine the whole time. A trick that might work, or may just keep the sysadmin occupied while the problem goes away on its own, is to go into the settings and change something (i.e. break it), reboot, then go back into settings and reset the thing that you broke.

(You could also try wearing a hat in a silly manner while standing inside a circle playing the clarinet badly -- it works for sea bears <-- silly Sponge Bob reference.)

When Mail gets into one of these frenzies, I've found what often works is to simply hit the cancel button on the annoying message, then select the affected account and hit Get Mail and it usually relents...until the next time. This seems to happen in sporadic episodes.