formatear texto en negritas

[Azrael666]

prueba asi:

$mensaje="<strong>".$remitente."</strong> thought about you while visiting Peru For Less and has recommended the site to you:\n$recibe\n\n
Peru For Less provides quality travel and tours to Peru and Latin America for the best possible prices imaginable.";


metiendo $remitente entre los ". y ." a ver si tira...