I am probably way behind the times, but in thinking of ways to sell and track a new product I learned about Email Tracking Software. I think it would be a good way to know if the prospective clients have checked out my emails or gather metrics about the effectiveness of email as a sales tool to these potential clients.

Is this a scrupulous practice? Does virus protection software pick up this type of email? Do folks have any recommendations as to the type of software I try out? I don't want to try a software that is too expensive and would prefer a month to month or 3 month payment. I looked a little online, but any recommendations would be helpful.