The following are general instructions on setting up your email or directory service application so that it can look up Oregon State University email addresses. To setup the OSU Directory Service you need to setup your ldap client with these settings:

The name of the server: 
directory.oregonstate.edu

The port the server uses: 
Port 389

The search base, or how it searches the directory: 
o=orst.edu

For more information on configuring a variety of email clients see this central computer help document.