It seems any new website I make recently it doesn't seem to get sandboxed, but a few years ago around 2005/06 it would have been sandboxed.

Any thoughts?

According to Cutts at Pubcon 2-3 years ago, there is no such thing as a "sandbox". He said that for particular industries (probably those that are notorious for fly by night sites) the way their algo works it can give the "illusion" of a sandbox.

But again... you have to consider the source.

I read an information about sandbox that this is just happened if a new website being over optimized in short span? Is it true?

Originally Posted by cecille20

I read an information about sandbox that this is just happened if a new website being over optimized in short span? Is it true?

You cannot "over optimise"! It is just a euphenism for spamming by keyword stuffing