There are a large number of user options that you can set. To fully explore these options, review the manual. This setting is a good choice for dialup users. Under Incoming Mail, you can select either POP or IMAP configurations. In simple terms, you can downloads your email to your local computer, while the latter always stores the mail on the server.
POP is the most common choice.
This is a good option for users who are regular Pine users, and use Eudora only occasionally. If you enter zero days, your mail will be deleted from the server immediately after downloading, and your downloaded mail will be your only copies. Scroll further down the Category window and click the Miscellaneous icon. Whenever you delete a message in Eudora, it doesn't disappear completely, but goes into a special folder called Trash. If you check this box, your Trash bin will be emptied every time you close the program.