Receiving messages with POP3 without marking them as read

Question

Dear Support,

When we use POP3 protocol to retrieve messages from an Exchange 2013 POP3 connector and mail.dll command:

pop3.GetMessageByUID(strUID);

the messages are received and marked as read in server's OWA interface. I cannot use IMAP as the IMAP connector is not enabled and the client's administrator insist on not doing so.

Also POP3 mail.dll implementation does not have a command:

pop3.PeekMessageByUID(strUID);

If I follow the instructions of the following MS article:
https://technet.microsoft.com/en-us/library/dd789740(v=exchg.80).aspx

telnet SERVERNAME 110
USER XXX
PASS YYY
LIST
RETR ZZZ

the message ZZZ is retrieved but not marked as read.
What is the difference? Cab I perform in POP3 a pop3.PeekMessageByUID(strUID) command somehow?

Thank you,

Thomas Zavitsanos
Benefit Software

Answer 1

Please turn on logging - https://www.limilabs.com/blog/logging-in-mail-dll - you will see that both: Pop3.GetMessageByNumber and Pop3.GetMessageByUID use POP3 "RETR" command internally.

POP3 doesn't have the concept of unseen email.

There is no Pop3.PeekMessageByUID, because there is no such command or even concept in POP3 protocol.

You need to use IMAP email protocol if you want to peek messages, or set seen/unseen status.

As a side note:
Are you sure that you aren't deleting message with POP3? This may cause the server to mark message as seen.