(C) Download an IMAP Message Set

Demonstrates how to read a set of IMAP emails.

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

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#include <C_CkImap.h>
#include <C_CkMessageSet.h>
#include <C_CkEmailBundle.h>
#include <C_CkEmail.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkImap imap;
    BOOL fetchUids;
    HCkMessageSet messageSet;
    HCkEmailBundle bundle;
    BOOL headersOnly;
    HCkEmail email;
    int i;
    int numEmails;

    success = FALSE;

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

    imap = CkImap_Create();

    // Connect using TLS.
    CkImap_putSsl(imap,TRUE);
    CkImap_putPort(imap,993);
    success = CkImap_Connect(imap,"imap.example.com");
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    // Authenticate
    success = CkImap_Login(imap,"email_account_login","email_account_password");
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    // Select an IMAP mailbox
    success = CkImap_SelectMailbox(imap,"Inbox");
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    // Search for messages with the word "test" in the subject.
    fetchUids = TRUE;

    messageSet = CkMessageSet_Create();
    success = CkImap_QueryMbx(imap,"Subject test",fetchUids,messageSet);
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkMessageSet_Dispose(messageSet);
        return;
    }

    // Download the messages in a single call to FetchMsgSet.
    // 
    // This only makes sense if the number of emails to be downloaded is not too large.  
    // For example, you wouldn't want to download 10000 emails in a single call to FetchMsgSet.
    // Why? For two reasons:  (1) It could potentially cause an out-of-memory condition, and 
    // (2) it would take an extremely large amount of time.  The longer the amount of time,
    // the greater the likelihood of some kind of external networking or server problem occuring,
    // and if it happens, then you would need to re-download everything from the beginning again.
    // For large numbers of emails, it's better to loop over the emails in the message set
    // and download/process one at a time as shown here: Download IMAP Messages One at a Time
    // Downloading one message at a time makes it possible to resume the downloads rather than restart the entire operation all over again.

    // If the message set is reasonable in size, you can download all at once using FetchMsgSet:

    printf("Number of messages = %d\n",CkMessageSet_getCount(messageSet));

    bundle = CkEmailBundle_Create();
    headersOnly = FALSE;
    success = CkImap_FetchMsgSet(imap,headersOnly,messageSet,bundle);
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkMessageSet_Dispose(messageSet);
        CkEmailBundle_Dispose(bundle);
        return;
    }

    // Display the Subject and From of each email.
    email = CkEmail_Create();
    i = 0;
    numEmails = CkEmailBundle_getMessageCount(bundle);
    while (i < numEmails) {
        CkEmailBundle_EmailAt(bundle,i,email);

        printf("%s\n",CkEmail_getHeaderField(email,"Date"));
        printf("%s\n",CkEmail_subject(email));
        printf("%s\n",CkEmail_ck_from(email));
        printf("--\n");
        i = i + 1;
    }



    CkImap_Dispose(imap);
    CkMessageSet_Dispose(messageSet);
    CkEmailBundle_Dispose(bundle);
    CkEmail_Dispose(email);

    }