Hey - Just want to chime in with some quick thoughts here...I agree with the group that this should be addressed via hosting provider or or fixed via IIS..if possible, try to quickly check
I did want to mention a couple quick checks to run to decide if to redirect it to mixed case or lowercase. I tend to prefer lower case generally aesthetically but it is good for just informational purposes to see how Google treating the site already. As such I recommend
(i) Choosing the case that is reflected in the internal linking on your website
(ii) check your backlink profile before redirecting stuff on the site, is the case that you're using in your internal linking reflected in how other websites link to the website?
(iii) run a 'site:[yourdomainname.com]' in google to get an idea of what mix of pages
(iv) and gotta say it...please review your site in a staging enviornment and test a couple URL's before going live. Also, run a 'site:[yourdomainname.com]' a couple days after you launch the change to make sure there is nothing funny appearing in Google and that the redirects are behaving as they should, just to be safe.
"...using this: sages act out of constructs but they do not rely on them"