I've written an update checker routine for our apps which contacts our server via regular HTTP and naturally I had to provide configuration options for connections through proxy servers. Currently I'm only providing options for proxy name (or address) and port number plus an "auto-detect" option which simply reads those two values from Internet Explorer's settings in the registry.
However, I've seen a lot of applications which additionally provide options for a user name and password (and sometimes even further options for encryption protocols and such things).
I myself haven't encountered proxy servers that require authentication for quite some time and I also noticed that Internet Explorer also does not provide options to specify this.
So I wonder how common are these? Would I be locking users out by not providing these options?