In Entourage do the following:
Pull down "Entourage">Account Settings>Directory Service tab then trash ldap.yahoo.com.
Problem solved by a girl no less.
I use Entourage 11.4.0 (from Office 2004) for my email, which has an earthlink.net address. (I have OS 10.5.8 onan iBook G4.) Lately Entourage regularly, on its own hook, seeks to connect to "idap.yahoo.com" (whatever that is). I have to terminate the effort by hitting command + period. What causes this, and, more important, how can I make it go away for good? Thanks.