This will help you set multiple accounts for Eudora 5 & 6

Click on "Tools" then on "Personalities"

Right click on "Dominant" left click on "New"

Select "Create a new account".

Give a name to your account.

Enter then name of the person who will be using the account.

Enter your email address

Provided by your ISP

pop3.yourdomain.com

smtp.yourdomain.com

Click finish and you are all set up.