Created Unassigned: message id returns null [2814]

Hello,

I am trying to get message id but its value return is null.

var client = new ImapClient("imap.mail.com", 143, false);
if (client.Connect())
{
if (client.Login("sername, password)))
{

var inbox = client.Folders.Inbox;
var message = inbox.Search();
foreach(var msg in message)
{
Console.WriteLine("{0}",msg.MessageId);
}

Please help.