First, a word of advice: Don't use Outlook!
If you insist, then the following worked from Outlook Express under Windows XP Pro. Microsoft has so many versions of outlook floating around, none of this may apply to your current situation.
First select "Tools->Accounts..." from the drop down and then select the mail tab and the pop server.
Next click the properties button. Be sure to NOT select "Log on using Secure Password Authentication". Instead, select the Advanced tab.
Click the "This server requires a secure connection (SSL)" box. The port should change to 995.
Now the first time you check you mail, outlook will complain about an "Internet Security Warning". Click yes to continue and you should get your mail. This box only appears the first time you check your mail using outlook.
The permanent fix is to add r2d2's certificate to the trusted list.
Who knows how to do this ? I tried for several hours to get outlook to accept r2d2's certificate but it refused. If you know how, let me know and I'll add it to this page.
This completes the procedure. You should now be able to securely check your email on r2d2.