(Java) Mark IMAP Email as Read/Unread (Seen/Unseen)

Demonstrates how to mark emails as read or unread.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkImap imap = new CkImap();

    // Connect to an IMAP server.
    // Use TLS
    imap.put_Ssl(true);
    imap.put_Port(993);
    boolean success = imap.Connect("imap.someMailServer.com");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Login
    success = imap.Login("myLogin","myPassword");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Set PeekMode so that downloaded messages are not
    // automatically marked as seen.
    imap.put_PeekMode(true);

    // The NumMessages property contains the number of messages 
    // in the currently selected mailbox.
    int numMsgs = imap.get_NumMessages();
    if (numMsgs == 0) {
        return;
        }

    int i;
    for (i = 1; i <= numMsgs; i++) {
        // Download each email by sequence number (not UID)
        CkEmail email;
        email = imap.FetchSingle(i,false);
        if (imap.get_LastMethodSuccess() == false) {
            System.out.println(imap.lastErrorText());
            return;
            }

        // If desired, mark the email as SEEN.  There are two
        // ways to do it:

        // 1) Set the flag directly by using the sequence number
        // Indicate that we are passing a sequence number and
        // not a UID:
        boolean bIsUid = false;
        // Set the SEEN flag = 1 to mark the email as SEEN,
        // or set it to 0 to mark it as not-seen.
        success = imap.SetFlag(i,bIsUid,"SEEN",1);
        if (success != true) {
            System.out.println(imap.lastErrorText());
            return;
            }

        // 2) Alternatively, we can use the email object.
        // When an email is downloaded from the IMAP server
        // Chilkat will add a "ckx-imap-uid" header to the email.
        // This makes it possible to know the UID associated with
        // the email.  (This is not the sequence number, which may change
        // from session to session, but the UID which does not change.
        // The SetMailFlag method is identical to SetFlag, except
        // it gets the UID from the ckx-imap-uid header.
        // For example:
        success = imap.SetMailFlag(email,"SEEN",1);
        if (success != true) {
            System.out.println(imap.lastErrorText());
            return;
            }

        }

    // Disconnect from the IMAP server.
    success = imap.Disconnect();
  }
}