Sample code for 30+ languages & platforms
Dart Requires Chilkat v11.0.0+

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

Demonstrates how to mark emails as read or unread.

Chilkat Dart Downloads

Dart
import 'package:chilkat/chilkat.dart';

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

  final imap = CkImap();

  // Connect to an IMAP server.
  // Use TLS
  imap.ssl = true;
  imap.port = 993;
  try {
    imap.connect('imap.example.com');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Login
  try {
    imap.login('myLogin', 'myPassword');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Select an IMAP mailbox
  try {
    imap.selectMailbox('Inbox');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Set PeekMode so that downloaded messages are not
  // automatically marked as seen.
  imap.peekMode = true;

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

  final email = CkEmail();
  for (var i = 1; i <= numMsgs; i++) {
    // Download each email by sequence number (not UID)
    try {
      imap.fetchEmail(false, i, false, email);
    } on ChilkatException catch (e) {
      print(e.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:
    final bIsUid = false;
    // Set the SEEN flag = 1 to mark the email as SEEN,
    // or set it to 0 to mark it as not-seen.
    try {
      imap.setFlag(i, bIsUid, 'SEEN', 1);
    } on ChilkatException catch (e) {
      print(e.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:
    try {
      imap.setMailFlag(email, 'SEEN', 1);
    } on ChilkatException catch (e) {
      print(e.lastErrorText);
      return;
    }
  }

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