Augusto

Hello. First of all you need to copy your files to the new domain directory on server (by the way, did you add it on server?). Then you must edit ‘siteurl’ and ‘home’ (both from wp_options) on database (through phpMyAdmin or similar).

After It would be nice to redirect the old domain to the new one.

Maybe you could do something like this:

<?php $curauth = (isset($_GET['author_name'])) ? get_user_by('slug', $author_name) : get_userdata(intval($author));

	query_posts('post_type=post&showposts=5&author='.$curauth->ID.''); ?>
	<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
	       <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link: <?php the_title(); ?>"><?php the_title(); ?></a>
	<?php endwhile; else: ?>
	 <?php endif; ?>

Yes, it prevents. It is a good plugin that comes with WordPress. You probably have it installed on your server. Try to activate.

Are you using Akismet?

You could use SMTP to send all emails using your gmail. Take a look.