Thanks James,
But I said that I had the hack thing solved before to ask for help. Fortunately the site is not infected and/or blacklisted.
Also, before to ask for help, I backed my site and uploaded the latest WP update.
The problem is that I have the -function wp_mail() {}- message on top left corner and if I try to access to wp-admin all that I got is a white page withe that message on top left corner.
So the problem remains.
Cheers
Txomin