POP3: Close the connection
After the session is complete it is necessary to properly close the connection. This is done using Close() method.
Silent parameter specifies if the connection must be forceful and without proper logging out from the server (when Silent is set to true) or "QUIT" command must be sent to the server (when Silent is set to false).
Any messages, marked for deletion during the session, will be deleted only when the logout is graceful, and QUIT command is sent.
If the connection has been initiated but has not been successful, you need to call Close() method to ensure that resources allocated for the connection are properly freed.