Question

I am working with Perl and using Net::POP3…

My code is able to get all the mails however I could not find any method in the documentation that can distinguish between read and unread messages.

IMAP does that, so I wanted to know if the same applies to POP3?

PS:: ping() method in Net::POP3 is not listed as capability of Net::POP3

Answer 1

With POP3 it is not possible to distinguish between read or unread. It can only fetch and delete messages. All messages that have not been fetched by the client (which remembers that itself) are regarded as not new by the client if it fetches new messages. The server doesn’t care about the state of a message. It just gives you all the messages it has.

From Wikipedia:

POP supports simple download-and-delete requirements for access to
remote mailboxes (termed maildrop in the POP RFC’s).[3] Although most
POP clients have an option to leave mail on server after download,
e-mail clients using POP generally connect, retrieve all messages,
store them on the user’s PC as new messages, delete them from the
server, and then disconnect. Other protocols, notably IMAP, (Internet
Message Access Protocol) provide more complete and complex remote
access to typical mailbox operations.