My 3 notebooks have the in client free each with a different account of email, today all of them have lost the activation and no more active, what can be

It would be helpful to have a little more information. Did you get some error or warning? What happens when you enter the activation key again?

when I enter the key it informs that the computer violated the license policies, it only has an e-mail account registered in the emclient

If the message says “This computer cannot be activated due to a violation of our license policy. Please contact our sales department.”  it means you were banned for violating the license policy, probably because you were using a Free license for business use.

If you think that is an error, and you are using the license only for personal use, you can contact the sales department through their email address [email protected] and they will be able to assist you further.