Just try searching for your own domain name in the google search and if it does not appear in the result page, you should be well assured that your site has been de-indexed! Regards, RightMan
well : site:www.yourdomain.com can help you figure out. If you one day you have a lot less pages indexed, that could be an evidence
There are multiple types of penalties. 1. PR reduced / 0ed for homepage. It's not all that hard to detect But it's only a guess that a site with 1000s of backlinks with PR0 can be considered penalized 2. Deindexing / Domain name penalized: Sometimes the site is removed from the index completely and a site:www.domainname.tld query will give no results. At the same place sometimes though site:.... query works the domain name query doesn't show the site in result (in first few pages) 3. Keyword spam penalty: I have also seen ranks being penalized for just one keyword phrase (SERPs for others remain same).
Sometimes when I search for a website, google does display it in results, but also says "Did you mean someothersite.com ?" For example if i search for eastdelhi.info, I do see it in result in 3rd position, but also google suggests me this "Did you mean: eastdelhi.com " Does that signal some sort of penality ?