Here is the message from Juno Support.
What are Juno's outgoing mail server (SMTP) and incoming mail server (POP3) addresses? (I'd like to know if Juno supports POP, because I'd like to use another e-mail program, such as Outlook, Outlook Express, or Eudora, to check my Juno e-mail.)
At this time, you cannot use other e-mail programs to get or send your Juno e-mail. For this reason, Juno's POP3 and SMTP mail server addresses are not available. You can, however, check your Juno e-mail messages from any computer connected to the Web by logging on to Juno WebMail at http://webmail.juno.com. To use Juno WebMail, you don't have to create a new account or password to use Juno WebMail; just use the user name and password for your existing Juno account.