get the message on start up "This product does not have a valid licence......." On restart get the message to reactivate

reactivation

This can happen if you have not activated a license after the trial period, you are using the same license on more than one computer, or if your license was blocked for a suspected license violation.

If you have an activation key, you can go to Menu > Help > License, and click on the Activate button, then paste your activation key into the field provided. If you do not have an activation key, you can get a Free License for personal use at http://www.emclient.com/free-license. If you are using eM Client for commercial or business use, you can purchase a Pro License at http://www.emclient.com/purchase-em-client.

If you are using the license on more than one computer, you can register for additional Free Licenses using different email addresses, or purchase additional Pro Licenses. There is a substantial discount for purchasing multiple Pro License at one time.

If you received a notification that your license was being blocked because of a license violation, you need to contact eM Client and explain your usage. If it for personal use only, they may reactivate your license. If it is for commercial or business use, you need to purchase a Pro License.