(DataFlex) POP3: Download Most Recent Email (method 2)

How to ready the N most recent email from a POP3 server.

The POP3 protocol does not provide the ability to request the most recent email, nor does it provide the ability to download email based on read/unread status or any other criteria. The design principle behind POP3 is that it is a temporary holding store for incoming email and email clients or other applications will transfer email from the POP3 server to a local persistent store where it will be managed. Therefore, POP3 does not provide sophisticated functionality (as opposed to IMAP which has the opposite design philosophy: that email is maintained and organized on the server).

This example shows one possible way to retrieve the N most recent emails from a POP3 server. It downloads the complete list of UIDLs and then downloads the last N into a bundle object. It assumes that the UIDLs will be returned by the POP3 server ordered by date such that the 1st email in the UIDL list is the oldest, and the last email is the newest.

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

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

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMailman
    Variant vStUidls
    Handle hoStUidls
    Integer iStartIdx
    Integer n
    Integer iCount
    Variant vStUidls
2    Handle hoStUidls2
    Integer iEndIdx
    Integer i
    Variant vBundle
    Handle hoBundle
    Boolean iHeadersOnly
    Integer iNumBodyLines
    Variant vEmail
    Handle hoEmail
    String sTemp1

    Move False To iSuccess

    // This example assumes 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.
    Get Create (RefClass(cComChilkatMailMan)) To hoMailman
    If (Not(IsComObjectCreated(hoMailman))) Begin
        Send CreateComObject of hoMailman
    End

    // Set the POP3 server's hostname
    Set ComMailHost Of hoMailman To "pop.example.com"

    // Set the POP3 login/password.
    Set ComPopUsername Of hoMailman To "bob@example.com"
    Set ComPopPassword Of hoMailman To "****"

    // Get the complete list of UIDLs
    Get Create (RefClass(cComChilkatStringTable)) To hoStUidls
    If (Not(IsComObjectCreated(hoStUidls))) Begin
        Send CreateComObject of hoStUidls
    End
    Get pvComObject of hoStUidls to vStUidls
    Get ComFetchUidls Of hoMailman vStUidls To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the 10 most recent UIDLs
    // The 1st email is the oldest, the last email is the newest (usually)
    Move 0 To iStartIdx
    Get ComCount Of hoStUidls To n
    If (n = 0) Begin
        Showln "No email in the inbox."
        Procedure_Return
    End

    Move 10 To iCount
    If (n > 10) Begin
        Move (n - 10) To iStartIdx
    End
    Else Begin
        Move 0 To iStartIdx
    End

    Get Create (RefClass(cComChilkatStringTable)) To hoStUidls2
    If (Not(IsComObjectCreated(hoStUidls2))) Begin
        Send CreateComObject of hoStUidls2
    End

    Move (n - 1) To iEndIdx

    For i From iStartIdx To iEndIdx
        Get ComStringAt Of hoStUidls i To sTemp1
        Get ComAppend Of hoStUidls2 sTemp1 To iSuccess
    Loop

    // Download in full the 10 most recent emails:
    Get Create (RefClass(cComChilkatEmailBundle)) To hoBundle
    If (Not(IsComObjectCreated(hoBundle))) Begin
        Send CreateComObject of hoBundle
    End
    Move False To iHeadersOnly
    // numBodyLines is ignored when fetching full emails.
    Move 0 To iNumBodyLines
    Get pvComObject of hoStUidls2 to vStUidls2
    Get pvComObject of hoBundle to vBundle
    Get ComFetchUidlSet Of hoMailman vStUidls2 iHeadersOnly iNumBodyLines vBundle To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End
    Move 0 To i
    While (i < (ComMessageCount(hoBundle)))
        Get pvComObject of hoEmail to vEmail
        Get ComEmailAt Of hoBundle i vEmail To iSuccess
        Get ComFrom Of hoEmail To sTemp1
        Showln sTemp1
        Get ComSubject Of hoEmail To sTemp1
        Showln sTemp1
        Showln "----"

        Move (i + 1) To i
    Loop



End_Procedure