MailBox is a TIdMailBox property that represents the IMAP4 mailbox including Attributes, Flags, and Messages stored on the remote IMAP4 server. 

Resources are allocated for the MailBox property during initialization of the component, and freed and released in the Destroy method. 

MailBox is assigned during processing that occurs for the server response in either the SelectMailBox or ExamineMailBox methods, and can be updated in methods that select, retrieve or update messages on the IMAP4 server. 

Use SelectMailBox to select the current mailbox with read or write access. 

Use ExamineMailBox to select the current mailbox with read-only access. 

Please note that message instances stored in the MailBox may not contain the complete contents for messages. They may contain only the headers (and no message parts), based on the value of the RetrieveOnSelect property when the mailbox is selected (or examined). 

Use one of the RetrieveXxx or UIDRetrieveXxx methods to populate the list of envelopes, headers, and messages in the mailbox.

TIdMailBox Destroy SelectMailBox ExamineMailBox RetrieveOnSelect Retrieve UIDRetrieve