If the messages are still on your mail server in your INBOX,
you can read them using normal JavaMail access. Note
that the POP3 protocol provides no notion of "new" or "already
read" messages; see the FAQ.
If you're using POP3 in the common form where you download
all new messages to your desktop machine, remove them from
the server, and only keep them locally on your desktop machine,
then JavaMail isn't going to be able to find them on your server.
you will have the flag for the messages, depening on the flag value you can determine what state the message is
Javax.mail.Message
isSet(Flags.Flag flag)-- returns boolean depending upon the flag value
Flag values
ANSWERED
DELETED
DRAFT
FLAGGED
RECENT
SEEN
USER