(PureBasic) Process Large POP3 Mailbox

Demonstrates how to read email from a mailbox that may contain a large number of emails.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkMailMan.pb"
IncludeFile "CkEmailBundle.pb"
IncludeFile "CkStringArray.pb"

Procedure ChilkatExample()

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

    mailman.i = CkMailMan::ckCreate()
    If mailman.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkMailMan::setCkMailHost(mailman, "pop.example.com")

    CkMailMan::setCkPopUsername(mailman, "myLogin")
    CkMailMan::setCkPopPassword(mailman, "myPassword")

    CkMailMan::setCkMailPort(mailman, 995)
    CkMailMan::setCkPopSsl(mailman, 1)

    ; Get the list of UIDLs for all emails in the mailbox.
    sa.i = CkMailMan::ckGetUidls(mailman)
    If CkMailMan::ckLastMethodSuccess(mailman) = 0
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        ProcedureReturn
    EndIf

    i.i
    numEmails.i = CkStringArray::ckCount(sa)
    If numEmails = 0
        Debug "Mailbox is empty"
        CkMailMan::ckDispose(mailman)
        ProcedureReturn
    EndIf

    chunkSize.i = 6

    ; Download the emails in chunks of 6 emails each.
    chunkBeginIdx.i = 0
    chunkEndIdx.i = chunkSize - 1
    If chunkEndIdx >= numEmails
        chunkEndIdx = numEmails - 1
    EndIf

    saChunk.i = CkStringArray::ckCreate()
    If saChunk.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    While (chunkBeginIdx < numEmails)

        Debug Str(chunkBeginIdx) + " to " + Str(chunkEndIdx)

        ; Build a chunk of UIDLs.
        CkStringArray::ckClear(saChunk)
        For i = chunkBeginIdx To chunkEndIdx
            CkStringArray::ckAppend(saChunk,CkStringArray::ckGetString(sa,i))
        Next

        ; Log the UIDLs in this chunk...
        chunkStr.s = CkStringArray::ckSaveToText(saChunk)
        Debug chunkStr

        ; Download this chunk of email from the POP3 server.
        bundle.i = CkMailMan::ckFetchMultiple(mailman,saChunk)
        If CkMailMan::ckLastMethodSuccess(mailman) = 0
            Debug CkMailMan::ckLastErrorText(mailman)
            CkMailMan::ckDispose(mailman)
            CkStringArray::ckDispose(saChunk)
            ProcedureReturn
        EndIf

        Debug "Downloaded " + Str(CkEmailBundle::ckMessageCount(bundle)) + " emails."
        Debug "----"

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

        CkEmailBundle::ckDispose(bundle)

        ; Get the next chunk...
        chunkBeginIdx = chunkBeginIdx + chunkSize
        chunkEndIdx = chunkEndIdx + chunkSize
        If chunkEndIdx >= numEmails
            chunkEndIdx = numEmails - 1
        EndIf

    Wend

    CkStringArray::ckDispose(sa)



    CkMailMan::ckDispose(mailman)
    CkStringArray::ckDispose(saChunk)


    ProcedureReturn
EndProcedure