some days before i have problem with 404 errors.It was picking up but again it is showing many urls as 404 error.what should i do to fix the error?if i re-submit the sitemap then will the errors get removed?
First run Link Sleuth to find any broken links on your site and fix them. Rebuilt your sitemap.xml and resubmit it. Google Sitemaps also reports where the links are coming from that could be causing the 404's. i.e. any external links pointing to urls on your site that don't exist. If you have external links pointing to places on your site that don't exist then use 301 redirects in your htaccess to redirect the broken link to url that's appropriate.