' The following example codes demonstrate marking email as read/downloaded on POP3 server
' To get full sample projects, please download and install EAGetMail on your machine.
' To run it correctly, please change email server, user, password, folder, file name value to yours

Option Explicit 

Const MailServerPop3 = 0 
Const MailServerImap4 = 1 

Private m_uidlfile As String 
Private m_uidls As String 

Private oTools As New EAGetMailObjLib.Tools 

'==========================================================================================
' UIDL is the identifier of every email on POP3/IMAP4 server, to avoid retrieve
' the same email from server more than once, we record the email uidl retrieved every time
' if you delete the email from server every time and not to leave a copy of email on
' the server, then please remove all the function about uidl.
'==========================================================================================
Private Sub LoadUIDL() 
    m_uidls = "" 
    m_uidls = oTools.ReadTextFile(m_uidlfile, 0) 
End Sub 

Private Sub UpdateUIDL() 
    On Error GoTo ErrorHandleUpdateUIDL 
    oTools.WriteTextFile m_uidlfile, m_uidls, 0 
    On Error GoTo 0 
    Exit Sub 
ErrorHandleUpdateUIDL: 
    MsgBox "Update UIDL Error: " & Err.Description 
    On Error GoTo 0 
End Sub 

Private Sub SyncUIDL(ByRef oServer As EAGetMailObjLib.MailServer, ByRef infos) 
    Dim arLocal 
    Dim newuidls As String 
    Dim uidlpref As String 
    uidlpref = LCase(oServer.Server) & "#" & LCase(oServer.User) & " " 

    arLocal = Split(m_uidls, vbCrLf) 
    Dim i, Count 
    For i = LBound(arLocal) To UBound(arLocal) 
        Dim t As String 
        Dim bRemove As Boolean 
        bRemove = False 
        t = arLocal(i) 
        If Len(t) > Len(uidlpref) Then 
            Dim curPref 
            curPref = Left(t, Len(uidlpref)) 
            If StrComp(curPref, uidlpref, vbBinaryCompare) = 0 Then 

                Dim localuidl 
                localuidl = Mid(t, Len(uidlpref) + 1) 

                Dim bExistOnServer As Boolean 
                bExistOnServer = False 

                Dim x 
                For x = LBound(infos) To UBound(infos) 
                    If StrComp(infos(x).UIDL, localuidl, vbBinaryCompare) = 0 Then 
                        bExistOnServer = True 
                    Exit For 
                    End If 
                Next 
                If Not bExistOnServer Then 
                    bRemove = True 
                End If 
            End If 
        End If 

        If Trim(t) = "" Then 
            bRemove = True 
        End If 

        If Not bRemove Then 
            newuidls = newuidls & t & vbCrLf 
        End If 
    Next 

    m_uidls = newuidls 
End Sub 

Private Function FindExistedUIDL(ByRef oServer As EAGetMailObjLib.MailServer, _ 
        ByRef UIDL As String) As Boolean 
        Dim s As String 
        s = LCase(oServer.Server) & "#" & LCase(oServer.User) & " " & UIDL & vbCrLf 
        If InStr(1, m_uidls, s, vbBinaryCompare) > 0 Then 
            FindExistedUIDL = True 
        Else 
            FindExistedUIDL = False 
        End If 
End Function 

Private Sub AddUIDL(ByRef oServer As EAGetMailObjLib.MailServer, ByRef UIDL As String) 
        Dim s As String 
        s = LCase(oServer.Server) & "#" & LCase(oServer.User) & " " & UIDL & vbCrLf 
        m_uidls = m_uidls & s 
End Sub 

Private Sub Command1_Click() 
    Dim curpath As String 
    Dim mailbox As String 

    ' Create a folder named "inbox" under current directory
    ' to save the email retrieved.
    curpath = App.Path 
    mailbox = curpath & "\inbox" 
    m_uidlfile = curpath & "\uidl.txt" 
    oTools.CreateFolder mailbox 

    Dim oServer As New EAGetMailObjLib.MailServer 
    oServer.Server = "pop3.emailarchitect.net" 
    oServer.User = "test@emailarchitect.net" 
    oServer.Password = "testpassword" 
    oServer.Protocol = MailServerPop3 

    ' If your POP3 requires SSL connection
    ' Please add the following codes
    ' oServer.SSLConnection = True
    ' oServer.Port = 995

    On Error GoTo ErrorHandle: 
    Dim oClient As New EAGetMailObjLib.MailClient 
    oClient.LicenseCode = "TryIt" 

    oClient.Connect oServer 
    MsgBox "Connected" 

    ' UIDL is the identifier of every email on POP3/IMAP4 server, to avoid retrieve
    ' the same email from server more than once, we record the email uidl retrieved every time
    ' if you delete the email from server every time and not to leave a copy of email on
    ' the server, then please remove all the function about uidl.
    LoadUIDL 

    Dim infos 
    infos = oClient.GetMailInfos() 
    MsgBox UBound(infos) + 1 & " emails" 

    SyncUIDL oServer, infos 

    Dim i As Integer 
    For i = LBound(infos) To UBound(infos) 
        Dim info As EAGetMailObjLib.MailInfo 
        Set info = infos(i) 
        MsgBox "Index: " & info.Index & "; Size: " & info.Size & _ 
        "; UIDL: " & info.UIDL 

        ' If this email has not been downloaded before, then get it
        If Not FindExistedUIDL(oServer, info.UIDL) Then 

            ' Receive email from POP3 server
            Dim oMail As EAGetMailObjLib.Mail 
            Set oMail = oClient.GetMail(info) 

            MsgBox "From: " & oMail.From.Address & _ 
                vbCrLf & "Subject: " & oMail.Subject 

            Dim fileName As String 
            ' Generate a random file name by current local datetime,
            ' You can use your method to generate the filename if you do not like it
            fileName = mailbox & "\" & oTools.GenFileName(i) & ".eml 

            ' Save email to local disk
            oMail.SaveAs fileName, True 

            ' Add the email uidl to uidl file to avoid we retrieve it next time.
            AddUIDL oServer, info.UIDL 
            ' Do not delete the email
        End If 
    Next 

    ' Quit
    oClient.Quit 

    ' Update the uidl list to a text file and then we can load it next time.
    UpdateUIDL 
    Exit Sub 

ErrorHandle: 
    MsgBox Err.Description 
    ' Update the uidl list to a text file and then we can load it next time.
    UpdateUIDL 
End Sub