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

Demonstrates how to mark emails as read or unread.

Download: Chilkat .NET Assemblies

Chilkat.Imap imap = new Chilkat.Imap();

bool success;

//  Anything unlocks the component and begins a fully-functional 30-day trial.
success = imap.UnlockComponent("Anything for 30-day trial");
if (success != true) {
    textBox1.Text += imap.LastErrorText + "\r\n";
    return;
}

//  Connect to an IMAP server.
success = imap.Connect("mail.chilkatsoft.com");
if (success != true) {
    textBox1.Text += imap.LastErrorText + "\r\n";
    return;
}

//  Login
success = imap.Login("myLogin","myPassword");
if (success != true) {
    textBox1.Text += imap.LastErrorText + "\r\n";
    return;
}

//  Select an IMAP mailbox
success = imap.SelectMailbox("Inbox");
if (success != true) {
    textBox1.Text += imap.LastErrorText + "\r\n";
    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.
int numMsgs;
numMsgs = imap.NumMessages;
if (numMsgs == 0) {
    return;
}

int i;
for (i = 1; i <= numMsgs; i++) {
    //  Download each email by sequence number (not UID)
    Chilkat.Email email = null;
    email = imap.FetchSingle(i,false);
    if (email == null ) {
        textBox1.Text += imap.LastErrorText + "\r\n";
        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:
    bool bIsUid;
    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) {
        textBox1.Text += imap.LastErrorText + "\r\n";
        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) {
        textBox1.Text += imap.LastErrorText + "\r\n";
        return;
    }

}

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