can not receive or send email and end of demo window keeps coming up when ever i log on

When you first install eM Client, it will run in evaluation mode. That will last for 30 days after which send and receive will be disabled.

To continue using the application you will need to register a Free License if you will use the application for personal use only, or if you will use it for business or need more that 2 email accounts, then you will need to purchase a Pro License.

In either case, once you have the license activation key, you can enter it in Menu > Help > License, after which you will be able to use the application normally.