Eudora is nice, but not as good as Outlook Express.
If you have multiple POP3 e-mail accounts or a POP3 account and a hotmail account, you surely will find Eudora lacking somewhat.
Also, if there are more than one person using the same computer, you will be more comfortable with OE. For example, I and my wife both use the same computer at home. She has 2 e-mail accounts and I have 5. We have separate identities that helps us keep our mails separate. Also, all my mails from all accounts are in one place. If I want I can keep mails from different accounts in different folders and that will be done qutomatically with rules. And its pretty simple.
There are many many advanages that OE has over the other mail softwares. I can't list them all here. But its the best free mail client (software) available today.
As regards security threats, you can keep an updated copy of an AntiVirus like Norton AntiVirus or a free one like AVG (
http://www.grisoft.com) and be assured. I am using Outlook Express since last 4 years. Touch-wood, I have had no problems so far
