DataFlex

POP3: Download Most Recent Email (method 1)

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 headers into a bundle object, then sorts the bundle by date, and finally retrieves the most recent emails by UIDL.

Another alternative is to download the UIDL list and then assume that the 1st N UIDLs are the most recent.

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMailman
    Variant vBundle
    Handle hoBundle
    Boolean iKeepOnServer
    Boolean iHeadersOnly
    Integer iNumBodyLines
    Boolean iAscending
    Variant vStUidls
    Handle hoStUidls
    Integer n
    Variant vEmail
    Handle hoEmail
    Integer i
    Variant vBundle
2    Handle hoBundle2
    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 "myLogin"
    Set ComPopPassword Of hoMailman To "myPassword"

    // Read mail headers and one line of the body.
    Get Create (RefClass(cComChilkatEmailBundle)) To hoBundle
    If (Not(IsComObjectCreated(hoBundle))) Begin
        Send CreateComObject of hoBundle
    End
    Move True To iKeepOnServer
    Move True To iHeadersOnly
    Move 1 To iNumBodyLines
    Get pvComObject of hoBundle to vBundle
    Get ComFetchAll Of hoMailman iKeepOnServer iHeadersOnly iNumBodyLines vBundle To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Sort the bundle by date
    Move False To iAscending
    Send ComSortByDate To hoBundle iAscending

    // Get the 10 most recent UIDLs
    Get Create (RefClass(cComChilkatStringTable)) To hoStUidls
    If (Not(IsComObjectCreated(hoStUidls))) Begin
        Send CreateComObject of hoStUidls
    End
    Get ComMessageCount Of hoBundle To n
    If (n > 10) Begin
        Move 10 To n
    End

    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End
    Move 0 To i
    While (i < n)
        Get pvComObject of hoEmail to vEmail
        Get ComEmailAt Of hoBundle i vEmail To iSuccess
        Get ComUidl Of hoEmail To sTemp1
        Get ComAppend Of hoStUidls sTemp1 To iSuccess
        Move (i + 1) To i
    Loop

    // Download in full the 10 most recent emails:
    Get Create (RefClass(cComChilkatEmailBundle)) To hoBundle2
    If (Not(IsComObjectCreated(hoBundle2))) Begin
        Send CreateComObject of hoBundle2
    End
    Move False To iHeadersOnly
    // numBodyLines is ignored if we're fetching the full emails.
    Get pvComObject of hoStUidls to vStUidls
    Get pvComObject of hoBundle2 to vBundle2
    Get ComFetchUidlSet Of hoMailman vStUidls iHeadersOnly iNumBodyLines vBundle2 To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Move 0 To i
    While (i < (ComMessageCount(hoBundle2)))
        Get pvComObject of hoEmail to vEmail
        Get ComEmailAt Of hoBundle2 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