Search an IMAP Mailbox

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Demonstrates the Chilkat Imap.QueryMbx method, which searches the selected mailbox using IMAP search criteria and stores the matching message identifiers in a MessageSet. If bUid is true, the identifiers are UIDs; otherwise they are sequence numbers. This example finds unseen messages and lists their UIDs.

Background: IMAP search runs on the server, so you can find matching messages without downloading them. The criteria string is standard IMAP search syntax — for example UNSEEN, FROM "alice@example.com", SUBJECT "invoice", or SINCE 1-Jan-2026 — and terms can be combined. The result is a MessageSet of identifiers you then fetch, flag, copy, or move. Requesting UIDs (bUid = true) is preferred because UIDs remain valid across sessions.

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bool success = false;

//  Demonstrates the Imap.QueryMbx method, which searches the selected mailbox using IMAP
//  search criteria and stores the matching message identifiers in a MessageSet.  If bUid is
//  true, the identifiers are UIDs; otherwise they are sequence numbers.

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

imap.Ssl = true;
imap.Port = 993;

success = imap.Connect("imap.example.com");
if (success == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

success = imap.Login("user@example.com","myPassword");
if (success == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

success = imap.SelectMailbox("Inbox");
if (success == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

//  Search for unseen (unread) messages, returning their UIDs.
Chilkat.MessageSet msgSet = new Chilkat.MessageSet();
success = imap.QueryMbx("UNSEEN",true,msgSet);
if (success == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

//  Iterate the matching message identifiers.
int n = msgSet.Count;
Debug.WriteLine("Matching messages: " + Convert.ToString(n));
int i;
for (i = 0; i <= n - 1; i++) {
    Debug.WriteLine("UID: " + Convert.ToString(msgSet.GetId(i)));
}

success = imap.Disconnect();
if (success == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}