E-Mail Problem

Hello, we are using OS 9.2.2. We cannot
receive e-mail using any client (netscape,
entourage, outlook express). We can send
mail. We get the error 23012, I looked it up
and it just tells me the problem, and not how
to resolve. We setupthe account on another
mac and it works fine, I tried setting up a
different account on this MAC and it has the
same problem. Any Ideas.

Thanks.