(PureBasic) 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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

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

Procedure ChilkatExample()

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

    success.i

    ; Set the POP3 server's hostname
    CkMailMan::setCkMailHost(mailman, "pop.someMailServer.com")

    ; Set the POP3 login/password.
    CkMailMan::setCkPopUsername(mailman, "myLogin")
    CkMailMan::setCkPopPassword(mailman, "myPassword")

    ; Read mail headers and one line of the body.
    bundle.i = CkMailMan::ckGetAllHeaders(mailman,1)
    If CkMailMan::ckLastMethodSuccess(mailman) = 0
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        ProcedureReturn
    EndIf

    ; Sort the bundle by date
    ascending.i = 0
    CkEmailBundle::ckSortByDate(bundle,ascending)

    ; Get the 10 most recent UIDLs
    saUidls.i = CkStringArray::ckCreate()
    If saUidls.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    n.i = CkEmailBundle::ckMessageCount(bundle)
    If n > 10
        n = 10
    EndIf

    i.i = 0
    email.i
    While i < n
        email = CkEmailBundle::ckGetEmail(bundle,i)
        success = CkStringArray::ckAppend(saUidls,CkEmail::ckUidl(email))
        CkEmail::ckDispose(email)

        i = i + 1
    Wend

    CkEmailBundle::ckDispose(bundle)

    ; Download in full the 10 most recent emails:
    bundle2.i = CkMailMan::ckFetchMultiple(mailman,saUidls)
    If CkMailMan::ckLastMethodSuccess(mailman) = 0
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        CkStringArray::ckDispose(saUidls)
        ProcedureReturn
    EndIf

    i = 0
    While i < CkEmailBundle::ckMessageCount(bundle2)
        email = CkEmailBundle::ckGetEmail(bundle2,i)
        Debug CkEmail::ckFrom(email)
        Debug CkEmail::ckSubject(email)
        Debug "----"
        CkEmail::ckDispose(email)

        i = i + 1
    Wend


    CkMailMan::ckDispose(mailman)
    CkStringArray::ckDispose(saUidls)


    ProcedureReturn
EndProcedure