DoAlert is a public method used to trigger the OnAlert event handler using the value specified in AMsg. 

DoAlert is a procedure that implements event notification for alert messages in an IMAP4 response. 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. 

DoAlert signals the OnAlert event handler for the current IMAP4 client instance using the value in AMsg for the alert message. Applications must assign a procedure to the OnAlert event handler to allow responding to the event notification. 

Please note that IMAP servers rarely implement alerts.

OnAlert SelectMailBox ExamineMailBox AppendMsg TIdAlertEvent