TIdAlertEvent is an event type signalled to allow an IMAP4 client to receive alert messages. Alert messages can occur in results from an IMAP4 command that selects the current mailbox, or appends a new message to a mailbox. TIdAlertEvent event are generated when the alert is parsed from the results from the command.
TIdAlertEvent allows the IMAP4 client to perform an operation by signalling the TIdIMAP4.OnAlert event handler.