Process Large POP3 Mailbox

Demonstrates how to read email from a mailbox that may contain a large number of emails (on the order of thousands of emails or more).

Download Chilkat Email ActiveX for POP3 / SMTP

'  The mailman object is used for receiving (POP3)
'  and sending (SMTP) email.
Dim mailman As New ChilkatMailMan2

'  Any string argument automatically begins the 30-day trial.
Dim success As Long
success = mailman.UnlockComponent("30-day trial")
If (success <> 1) Then
    MsgBox "Component unlock failed"
    Exit Sub
End If

'  Set the POP3 server's hostname
mailman.MailHost = "mail.chilkatsoft.com"

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

'  First, get the list of UIDLs for all emails in the mailbox.
Dim sa As CkStringArray
Set sa = mailman.GetUidls()
Dim i As Long
Dim numEmails As Long
numEmails = sa.Count

'  Download the emails in chunks of 10 emails each.
Dim chunkBeginIdx As Long
chunkBeginIdx = 0
Dim chunkEndIdx As Long
chunkEndIdx = 9
If (chunkEndIdx >= numEmails) Then
    chunkEndIdx = numEmails - 1
End If

Dim saChunk As New CkStringArray
Do While (chunkEndIdx < (numEmails - 1))

    '  Build a chunk of 10 UIDLs.
    saChunk.Clear 
    For i = chunkBeginIdx To chunkEndIdx
        saChunk.Append sa.GetString(i)
    Next

    '  Display the UIDLs in this chunk...
    Dim chunkStr As String
    chunkStr = saChunk.SaveToText()
    Text1.Text = Text1.Text & chunkStr & vbCrLf
    Text1.Text = Text1.Text & "----" & vbCrLf & vbCrLf

    '  Download this chunk of email from the POP3 server.
    Dim bundle As ChilkatEmailBundle2
    Set bundle = mailman.FetchMultiple(saChunk)
    If (bundle Is Nothing ) Then
        MsgBox mailman.LastErrorText
        Exit Sub
    End If

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

    '  Get the next chunk...
    chunkBeginIdx = chunkBeginIdx + 10
    If (chunkBeginIdx >= numEmails) Then
        Exit For
    End If

    chunkEndIdx = chunkEndIdx + 10
    If (chunkEndIdx >= numEmails) Then
        chunkEndIdx = numEmails - 1
    End If

Loop