The RecentMessages property returns the number of
messages which have been recently added to the currently selected
mailbox. This property is particularly useful when the INBOX
mailbox is selected, since it enables the application to check if
any new messages have arrived.
This property value is only meaningful when connected to an IMAP
server. If the control is connected to a POP3 server, this property
will always return the same value as the MessageCount
property.