i'm getting over 500,000 crawl errors in google webmaster tools for one of my websites. these are 'not found' errors because the files were deleted over 6 months ago.. i have no idea how to get rid of them.. i know google has a tool to 'remove URL's' but i'd have to key in over 500,000.. why aren't these going away? and can i use a 301 redirect to send these to the home page of my website. since most of the pages start with a certain word like 'category' or 'display?', can i use a wildcard in my htaccess file to redirect groups of them? and what would that redirect look like? thanks for your help in advance.
Make sure that those pages are not linked on any page or any other websites otherwise it will be crawled by search engine. Also, it takes long time to remove all URLs. You can set 301 redirection but I not sure if it affects SEO for your website or not. - Kailash