Microsoft Exchange Server 2016 Cumulative Edition 15.1.1531.3
I observed a HTTP request from the server to a web site URL on port 80, with user agent Mozilla. Though Mozilla has never been installed, nor anybody were connected at this request time. So this request remains unexplained. Any idea ? Thx.
That's expected, to provide a more or less standard user agent string to inform the service or server on the client being used (IE desktop, mobile), specifying application type, OS, vendor/version, etc. through the user agent. 'Mozilla' indicates the client is Mozilla compatible. Some services drop the request - purposely - when empty user agent strings are provided (we all know the redirects to 'use browser X to view this page).