Eudora Port settings

I'm using a simple proxy server for internet connection sharing on a Windows 2000 network. Internet works great, but to access email (POP3 and SMTP) on the workstations I've had to setup Mapped TCP links. This links certain port numbers to the incoming and outgoing mail server of the ISP.
This means in the email client the POP3 port must be changed from 110 to 44110 (or any other port) and the SMTP port from 25 to 4425. Anyway, this works fine in outlook express, but I'm have some trouble changing these settings in Eudora 4. According the documentation these settings can be changed by adding lines to the settings area of the EUDORA.INI file:

[Settings]
POPPort=44110
SMTPPort=4425

I've added these lines to the INI file, but whenever checking mail in Eudora I get error 10061. Outlook Express works ok though, so the problem is obviously with Eudora.