(Java) Fetch Full Email Given Email Header

When you fetch email headers using UIDs instead of sequence numbers, the email object (which includes only the header) will have auto-generated ckx-imap-* headers. These headers provide details like the UID and attachments. The IMAP UID is found in the ckx-imap-uid header. Additionally, the ckx-imap-isUid header indicates whether the email header was downloaded by UID, showing YES or NO. Since sequence numbers can change if emails are deleted, UIDs are essential for downloading the correct full email.

The Chilkat Email object offers a GetImapUid method to retrieve the UID from the ckx-imap-uid header. This UID can be used to fetch the full email.

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

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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[])
  {
    boolean success = false;

    // This example requires 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);
    success = imap.Connect("imap.example.com");
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Login
    success = imap.Login("***","***");
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

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

    CkEmail emailHeader = new CkEmail();
    CkEmail emailFull = new CkEmail();

    int uid = 2014;
    boolean isUid = true;

    // Fetch only the email header
    success = imap.FetchEmail(true,uid,isUid,emailHeader);
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Now fetch the full email
    int uidFromCkxHeader = emailHeader.GetImapUid();
    if (uidFromCkxHeader < 0) {
        // Failed. 
        System.out.println("No ckx-imap-uid header was found.");
        return;
        }

    success = imap.FetchEmail(false,uid,isUid,emailFull);
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // OK, we have the full email, do whatever we want...

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