(Excel) Process Large POP3 Mailbox

Demonstrates how to read email from a mailbox that may contain a large number of emails.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim mailman As Chilkat.MailMan
Set mailman = Chilkat.NewMailMan

mailman.MailHost = "pop.example.com"

mailman.PopUsername = "myLogin"
mailman.PopPassword = "myPassword"

mailman.MailPort = 995
mailman.PopSsl = True

' Get the list of UIDLs for all emails in the mailbox.

Set sa = mailman.GetUidls()
If (mailman.LastMethodSuccess = False) Then
    Debug.Print mailman.LastErrorText
    Exit Sub
End If


numEmails = sa.Count
If (numEmails = 0) Then
    Debug.Print "Mailbox is empty"
    Exit Sub
End If


chunkSize = 6

' Download the emails in chunks of 6 emails each.

chunkBeginIdx = 0

chunkEndIdx = chunkSize - 1
If (chunkEndIdx >= numEmails) Then
    chunkEndIdx = numEmails - 1
End If

Dim saChunk As Chilkat.StringArray
Set saChunk = Chilkat.NewStringArray
Do While (chunkBeginIdx < numEmails)

    Debug.Print chunkBeginIdx; " to "; chunkEndIdx

    ' Build a chunk of UIDLs.
    saChunk.Clear 
    For i = chunkBeginIdx To chunkEndIdx
        Dim success As Boolean
        success = saChunk.Append(sa.GetString(i))
    Next

    ' Log the UIDLs in this chunk...

    chunkStr = saChunk.SaveToText()
    Debug.Print chunkStr

    ' Download this chunk of email from the POP3 server.

    Set bundle = mailman.FetchMultiple(saChunk)
    If (mailman.LastMethodSuccess = False) Then
        Debug.Print mailman.LastErrorText
        Exit Sub
    End If

    Debug.Print "Downloaded "; bundle.MessageCount; " emails."
    Debug.Print "----"

    ' Process the bundle...
    ' (your application's processing code goes here...)

    ' Get the next chunk...
    chunkBeginIdx = chunkBeginIdx + chunkSize
    chunkEndIdx = chunkEndIdx + chunkSize
    If (chunkEndIdx >= numEmails) Then
        chunkEndIdx = numEmails - 1
    End If

Loop