What do you mean by sandbox? I asked a lot about sandbox here in DP but most of times answered that there is no real existence of sandbox or like that. You may be penalized.Verify that first.Thanks
When your site gets sandboxed by Google (or temporarily removed from the search results), you should basically continue to work hard on your site to create valuable content and build quality backlinks. This will help Google trust you and within 1 to 6 months maximum, you should be out of the Google Sandbox with an improved site ready for good conversions!
you can ask for re-inclusion, I heard that before... or you try to create new site and re-index it. I haven't hear of any website that got into sandbox and get index again.
you can request google for re-inclusion, but its highly unlikely that the same site will be re-included. I would recommend you to change some content on your site before requesting google.regards
Yes may be there is no existence of Google Sand Box but no one is sure about that but My website is penalized and almost exactly happened to my website that is described about sandBox. 1.My site is totally disappeared from Google even not found by entering full Url 2. My website is not cached from last six month.
You try to build the high page rank links and add unique content to your website. and build links continuously and target long tail keywords.