Logging in one by one, to all the accounts on the machine? (which is what I think you will have to do, unless I misunderstand your confusing question). Indeed, as I think you mean to say (?), you can only receive mail for one particular account at a time, with each POP3 JavaMail session, so you have to close the old one and open a new one, for each new account/mailbox that you want to read.



IMAP is more flexible than POP, since you can subscribe to multiple shared folders, including other accounts' "mailboxes". So if there is also an IMAP server on the same machine, maybe you could log in to it in one session, and read several account mailboxes from there.