440 Login Time-out
HTTP response status code 440 Login Time-out is an unofficial client error specific to the Microsoft IIS web server and is returned to indicate that the client’s HTTP session has expired and they need to log in again.
When the 440 Login Time-out status code is received, it means that client Authentication is required because the current HTTP session has expired. It occurs with Microsoft Exchange 2003 and Microsoft Exchange 2007 servers, as well as the Microsoft IIS web server.
Search engines like Google will not index a URL with 440 Login Time-out response status, and consequently, URLs that have been indexed in the past but are now returning this HTTP status code will be removed from the search results.
The 440 Login Time-out status code is a Microsoft-specific client error that is sent when a client’s HTTP session has expired and needs to log in again.