I want that everyone who enter my site can e-mail me to my e-mail accout. (without open outlook).
how can I do it?
Since you do not want the website visitor to have his email client popup, then you cannot use the mailto technique.
First you would need to tell us what technologies your host supports. ASP, PHP, Perl, FrontPage?
It can be done many different ways on the backend but the frontend is always the same. You create a form and the action for the form would be the backend script. The backend script would then take care of sending the email.