(Visual FoxPro) Reading Unread POP3 Email

The POP3 protocol does not provide the ability to ask the server which emails are "unread". Furthermore, a pure POP3 server does not even keep this information. Some servers, such as Exchange Server, expose both POP3 and IMAP interfaces. In these cases, information about read/unread status exists on the server, but it is only available via the IMAP protocol. Email clients such as Outlook and Thunderbird keep read/unread information on the client computer. This example demonstrates how UIDLs can be saved to track and read "unread" email.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loMailman
LOCAL loSaSeenUidls
LOCAL lnSuccess
LOCAL loSaUidls
LOCAL loSaUnseenUidls
LOCAL i
LOCAL n
LOCAL loBundle
LOCAL loEmail

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* The mailman object is used for receiving (POP3) 
* and sending (SMTP) email.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.MailMan')
loMailman = CreateObject('Chilkat.MailMan')

* Set the POP3 server's hostname
loMailman.MailHost = "pop.someMailServer.com"

* Set the POP3 login/password.
loMailman.PopUsername = "***"
loMailman.PopPassword = "***"

* You may keep a list of already-seen UIDLs in a text file:
* If this is the first time you're running this example,
* create an empty text file named "seenUidls.txt"
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringArray')
loSaSeenUidls = CreateObject('Chilkat.StringArray')
lnSuccess = loSaSeenUidls.LoadFromFile("seenUidls.txt")
IF (lnSuccess <> 1) THEN
    ? "failed to load seenUidls.txt"
    RELEASE loMailman
    RELEASE loSaSeenUidls
    CANCEL
ENDIF

* Get the complete list of UIDLs on the mail server.
loSaUidls = loMailman.GetUidls()
IF (loMailman.LastMethodSuccess = 0) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loSaSeenUidls
    CANCEL
ENDIF

* Create a new string array object (it's an object, not an actual array)
* and add the UIDLs from saUidls that aren't already seen.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringArray')
loSaUnseenUidls = CreateObject('Chilkat.StringArray')

i = 0
n = loSaUidls.Count
DO WHILE i < n
    IF (loSaSeenUidls.Contains(loSaUidls.GetString(i)) <> 1) THEN
        lnSuccess = loSaUnseenUidls.Append(loSaUidls.GetString(i))
    ENDIF

    i = i + 1
ENDDO

IF (loSaUnseenUidls.Count = 0) THEN
    ? "No unseen emails!"
    RELEASE loSaUidls
    RELEASE loMailman
    RELEASE loSaSeenUidls
    RELEASE loSaUnseenUidls
    CANCEL
ENDIF

* Download in full the unseen emails:
loBundle = loMailman.FetchMultiple(loSaUnseenUidls)
IF (loMailman.LastMethodSuccess = 0) THEN
    ? loMailman.LastErrorText
    RELEASE loSaUidls
    RELEASE loMailman
    RELEASE loSaSeenUidls
    RELEASE loSaUnseenUidls
    CANCEL
ENDIF

i = 0
DO WHILE i < loBundle.MessageCount
    loEmail = loBundle.GetEmail(i)
    ? loEmail.From
    ? loEmail.Subject
    ? "----"
    RELEASE loEmail
    i = i + 1
ENDDO

* Save saUidls to "seenUidls.txt"
lnSuccess = loSaUidls.SaveToFile("seenUidls.txt")

RELEASE loSaUidls

RELEASE loMailman
RELEASE loSaSeenUidls
RELEASE loSaUnseenUidls