Website Sitemaps are very important
Many feel Search Engines will just naturally find all your pages and index them.
For me and my websites I have 2 that search engines visit so often the numbers are crazy and sitemaps really are only used to see what hasn't been indexed.
Use your Webmaster Tools and create your site maps.
I've had to create them manually and do have most setup to be dynamically updated when I add pages.
If your code is in ASP Classic I'm sharing one of my many XML ASP Classic pages that creates sitemaps from database tables which store your page names. If you don't have that I'll share with you how to create one.
You should have a sitemap.
Go to my Robots.txt file of this site and then compare that with my ASP Classic site and you'll see why it's very important to have your sitemaps created perfectly.