Hi, I have submitted my sitemap to google 35,000 links, 2,400 indexed before the sitemap submission but now is down to 1,000 pages indexed!! could this be?!!! Regards
A lot of sites have had pages de-indexed recently. It is possible that this is not related to your sitemap submission.
This is normal, it takes a while to go over all the content again before indexing. Resubmitting is for major content changes or if you have removed a lot of content, etc. It's basically telling it to start over. Also don't re-submit your sitemap to often, this might sandbox you or just take longer, google will come along and re-read it by itself ever now and then anyways. Just add it to Google Webmasters and/or inside your robots.txt so it knows where to find it and leave it to do it's stuff, might take a week. You don't even have to give a sitemap.xml and robots.txt, but it's recommended for larger sites. Google does clean ups every now and then which might de-index some of the pages not accessed as much.
Try and submit your sitemap again that shpuld help your pages to start getting indexed again. Don't submit it too many times thought because you wanna run the risk of getting sandboxed thats the last thing you want!
Keep patient, It take a time for robots to crawl and reindex pages, I agree with Azzaboi that don't re submit sitemap it might be a sandbox or when robots come to your site, new sitemap not been uploaded. Thanks