Remove the extra symbol “<>” in WordPress registration email

Solution:

Filter the wp_mail function:

add_filter( 'wp_mail','remove_tags' );
function remove_tags( $args ){
    $args['message'] = str_replace( '<', '', $args['message'] );
    $args['message'] = str_replace( '>', '', $args['message'] );
    return $args;    
}

More information here: wp_mail.