HTML:

<div class="social">
<ul>
<li><a class="butt1" href="mailto:info@giogiogio.it"></a></li>
<li><a class="butt2" href="#"></a></li>
</ul>
</div>
CSS:

.social a{
background-image: url(../img/social.png);
display: inline-block;
list-style: none;
width: 80px;
height: 80px;
}


.butt2{
background-position: 80px 0;
}


.social .butt1:hover{
background-position: -0px -80px;
}
.social .butt2:hover{
background-position: 80px 80px;
}


.social ul li{
list-style-type: none;
display: inline;
}


ul{
padding: 0;
}