When you use rentacoder, etc....the email corresponcence is supposed to be through them on there site only only.....

If you go outside these to a programmer, writer, etc....make sure in your contract that you have a clause stating that all email correspondence is a binding part of the contract....very important clause!!!

And if later after you use the other services you start working with the person you used through the services of rentacoder, etc....make sure you have a formal contract with them and include the same email clause.