(VBScript) Reading Unread POP3 Email

The POP3 protocol cannot determine which emails are "unread," and pure POP3 servers do not store this information. Servers like Exchange Server, offering both POP3 and IMAP interfaces, do contain read/unread data, but it's only accessible through IMAP. Email clients like Outlook and Thunderbird store read/unread statuses on the client side. The example demonstrates using UIDLs to track and manage "unread" emails.

Note: This example requires Chilkat v11.0.0 or greater.

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

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

' 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.
set mailman = CreateObject("Chilkat.MailMan")

' Set the POP3 server's hostname
mailman.MailHost = "pop.example.com"

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

' Keep a records of already-seen UIDLs in hash table serialized to an XML file.
seenUidlsPath = "c:/temp/seenUidls.xml"

set sbXml = CreateObject("Chilkat.StringBuilder")
set htSeenUidls = CreateObject("Chilkat.Hashtable")
set fac = CreateObject("Chilkat.FileAccess")
If (fac.FileExists(seenUidlsPath) = 1) Then
    success = sbXml.LoadFile(seenUidlsPath,"utf-8")
    If (success = 0) Then
        outFile.WriteLine(sbXml.LastErrorText)
        WScript.Quit
    End If

    success = htSeenUidls.AddFromXmlSb(sbXml)
End If

' Get the complete list of UIDLs on the mail server.
set stUidls = CreateObject("Chilkat.StringTable")
success = mailman.FetchUidls(stUidls)
If (success = 0) Then
    outFile.WriteLine(mailman.LastErrorText)
    WScript.Quit
End If

' Build a list of unseen UIDLs
set stUnseenUidls = CreateObject("Chilkat.StringTable")

i = 0
count = stUidls.Count
Do While i < count
    uidl = stUidls.StringAt(i)
    If (htSeenUidls.Contains(uidl) <> 1) Then
        success = stUnseenUidls.Append(uidl)
    End If

    i = i + 1
Loop

If (stUnseenUidls.Count = 0) Then
    outFile.WriteLine("No unseen emails!")
    WScript.Quit
End If

' Download the unseen emails, adding each UIDL to the "seen" hash table.
set email = CreateObject("Chilkat.Email")

count = stUnseenUidls.Count
i = 0
Do While i < count
    ' Download the full email.
    uidl = stUnseenUidls.StringAt(i)
    success = mailman.FetchByUidl(uidl,0,0,email)
    If (success = 0) Then
        outFile.WriteLine(mailman.LastErrorText)
        WScript.Quit
    End If

    outFile.WriteLine(i)
    outFile.WriteLine("From: " & email.From)
    outFile.WriteLine("Subject: " & email.Subject)

    ' Add this UIDL to the "seen" hash table.
    success = htSeenUidls.AddStr(uidl,"")

    i = i + 1
Loop

success = mailman.Pop3EndSession()

' Update the "seen" UIDLs file.
sbXml.Clear 
success = htSeenUidls.ToXmlSb(sbXml)
success = sbXml.WriteFile(seenUidlsPath,"utf-8",0)
If (success = 0) Then
    outFile.WriteLine(sbXml.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("Success.")

outFile.Close