(DataFlex) How to Download Messages in MessageSet One at a Time

If a message set contains a huge number of emails, it's NOT a good idea to try to download all at once into an email bundle using a method such as FetchBundle. It's better to iterate over the messages in the set to download one by one.

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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoImap
    Boolean iSuccess
    Boolean iFetchUids
    Variant vMessageSet
    Handle hoMessageSet
    Integer i
    Variant vEmail
    Handle hoEmail
    String sTemp1
    String sTemp2
    Integer iTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatImap)) To hoImap
    If (Not(IsComObjectCreated(hoImap))) Begin
        Send CreateComObject of hoImap
    End

    // Connect using TLS.
    Set ComSsl Of hoImap To True
    Set ComPort Of hoImap To 993
    Get ComConnect Of hoImap "imap.example.com" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Authenticate
    Get ComLogin Of hoImap "email_account_login" "email_account_password" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Select an IMAP mailbox
    Get ComSelectMailbox Of hoImap "Inbox" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Search for messages and return a set of matching messages.
    // (This example will simply search for ALL messages.)
    Move True To iFetchUids
    Get ComSearch Of hoImap "ALL" iFetchUids To vMessageSet
    If (IsComObject(vMessageSet)) Begin
        Get Create (RefClass(cComChilkatMessageSet)) To hoMessageSet
        Set pvComObject Of hoMessageSet To vMessageSet
    End
    Get ComLastMethodSuccess Of hoImap To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComCount Of hoMessageSet To iTemp1
    Showln "Number of messages = " iTemp1

    Move 0 To i
    While (i < (ComCount(hoMessageSet)))
        Get ComGetId Of hoMessageSet i To iTemp1
        Get ComFetchSingle Of hoImap iTemp1 iFetchUids To vEmail
        If (IsComObject(vEmail)) Begin
            Get Create (RefClass(cComChilkatEmail)) To hoEmail
            Set pvComObject Of hoEmail To vEmail
        End
        Get ComLastMethodSuccess Of hoImap To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoImap To sTemp1
            Showln sTemp1
            Send Destroy of hoMessageSet
            Procedure_Return
        End

        Get ComFrom Of hoEmail To sTemp1
        Get ComSubject Of hoEmail To sTemp2
        Showln sTemp1 "; " sTemp2
        Send Destroy of hoEmail

        Move (i + 1) To i
    Loop

    Send Destroy of hoMessageSet

    Showln "OK"


End_Procedure