I'm encountering the same issue and am hoping for some more ideas.

I've completely deleted they keychain and created a new logon,.keychain. I've also tried a new outlook Identity. I've repaired permissions and repaired the keychain once the error is encoutered.

I've recently gone as far as creating a new OSX profile and reconfiguring all email accounts. This is of course on a new outlook identity since this is a new profile and of course this is a new keychain.

Any troubleshooting advice would be appreciated as I am running out of ideas.

This seems to have happened after the Maverick update. No more microsoft or apple udpates have been found.

*no exchange server, only IMAP and POP accounts.

[Original post was for Exchange account. All new questions regarding Mavericks need to be new for best results.]