I am currently generating a sitemap file dynamically using a HttpHandler, with a path set to sitemap.axd. This then returns xml content. No one at my office is certain if all search engines accept this extension or if they need .xml to parse. I know that I can submit it to Google through the webmaster tools and use robots.txt to indicate that the sitemap is sitemap.axd.

Is sitemap.axd accepted by all? If not, does anyone know which ones will or won't?

+2  A: 

The protocol agreed by the major search engines allows you to specify in your robots.txt file the location of your XML sitemap. There is a tendency in examples to name this 'sitemap.xml' but any name with or without any extension should work as long as the content at that location is XML.

The MIME type specified in the HTTP response might be required by some search engines to be one of a list of text or xml-ish types.