(PowerBuilder) 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

integer li_rc
oleobject loo_Mailman
oleobject loo_SaSeenUidls
integer li_Success
oleobject loo_SaUidls
oleobject loo_SaUnseenUidls
integer i
integer n
oleobject loo_Bundle
oleobject loo_Email

// 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.
loo_Mailman = create oleobject
li_rc = loo_Mailman.ConnectToNewObject("Chilkat_9_5_0.MailMan")
if li_rc < 0 then
    destroy loo_Mailman
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Set the POP3 server's hostname
loo_Mailman.MailHost = "pop.someMailServer.com"

// Set the POP3 login/password.
loo_Mailman.PopUsername = "***"
loo_Mailman.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"
loo_SaSeenUidls = create oleobject
li_rc = loo_SaSeenUidls.ConnectToNewObject("Chilkat_9_5_0.StringArray")

li_Success = loo_SaSeenUidls.LoadFromFile("seenUidls.txt")
if li_Success <> 1 then
    Write-Debug "failed to load seenUidls.txt"
    destroy loo_Mailman
    destroy loo_SaSeenUidls
    return
end if

// Get the complete list of UIDLs on the mail server.
loo_SaUidls = loo_Mailman.GetUidls()
if loo_Mailman.LastMethodSuccess = 0 then
    Write-Debug loo_Mailman.LastErrorText
    destroy loo_Mailman
    destroy loo_SaSeenUidls
    return
end if

// 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.
loo_SaUnseenUidls = create oleobject
li_rc = loo_SaUnseenUidls.ConnectToNewObject("Chilkat_9_5_0.StringArray")

i = 0
n = loo_SaUidls.Count
do while i < n
    if loo_SaSeenUidls.Contains(loo_SaUidls.GetString(i)) <> 1 then
        li_Success = loo_SaUnseenUidls.Append(loo_SaUidls.GetString(i))
    end if

    i = i + 1
loop

if loo_SaUnseenUidls.Count = 0 then
    Write-Debug "No unseen emails!"
    destroy loo_SaUidls
    destroy loo_Mailman
    destroy loo_SaSeenUidls
    destroy loo_SaUnseenUidls
    return
end if

// Download in full the unseen emails:
loo_Bundle = loo_Mailman.FetchMultiple(loo_SaUnseenUidls)
if loo_Mailman.LastMethodSuccess = 0 then
    Write-Debug loo_Mailman.LastErrorText
    destroy loo_SaUidls
    destroy loo_Mailman
    destroy loo_SaSeenUidls
    destroy loo_SaUnseenUidls
    return
end if

i = 0
do while i < loo_Bundle.MessageCount
    loo_Email = loo_Bundle.GetEmail(i)
    Write-Debug loo_Email.From
    Write-Debug loo_Email.Subject
    Write-Debug "----"
    destroy loo_Email
    i = i + 1
loop

// Save saUidls to "seenUidls.txt"
li_Success = loo_SaUidls.SaveToFile("seenUidls.txt")

destroy loo_SaUidls


destroy loo_Mailman
destroy loo_SaSeenUidls
destroy loo_SaUnseenUidls