A CodePen by PrithvirajBilla. Mail anim

index.html

<div id="bg"></div>
<div class="contact">
	<div class="envelope">
		<div class="top">
			<div class="outer"><div class="inner"></div></div>
		</div>
		<div class="bottom"></div>
		<div class="left"></div>
		<div class="right"></div>
		<div class="cover"></div>
		<div class="paper">
			<a class="call" href="tel:00000000"><i class="icon-phone"></i> 0 000 00 00</a>
			<a class="mail" href="mailto:mail@mail"><i class="icon-envelope"></i> mail@mail</a>
		</div>
	</div>
</div>

style.css

@import "//netdna.bootstrapcdn.com/font-awesome/3.0/css/font-awesome.css";

#bg {
		position: absolute;
		left: 0px;
		top: 0px;
		height: 100%;
		width: 100%;
		background: #ffffff; background: url(data:image/svg+xml;base64,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); background: -moz-radial-gradient(center, ellipse cover,  #ffffff 40%, #bbbbbb 100%); background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(40%,#ffffff), color-stop(100%,#bbbbbb)); background: -webkit-radial-gradient(center, ellipse cover,  #ffffff 40%,#bbbbbb 100%); background: -o-radial-gradient(center, ellipse cover,  #ffffff 40%,#bbbbbb 100%); background: -ms-radial-gradient(center, ellipse cover,  #ffffff 40%,#bbbbbb 100%); background: radial-gradient(ellipse at center,  #ffffff 40%,#bbbbbb 100%); filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ffffff', endColorstr='#bbbbbb',GradientType=1 );
}

.contact * { -webkit-backface-visibility: hidden; }

.paper:hover { color:#000; }

.contact { 
		position: absolute;
		left: 50%;
		top: 50%;
		margin-left: -125px;
		margin-top: -125px;
		height: 250px;
		width: 250px;
		background: rgba(0, 0, 0, 0.1);
		
		border-radius: 2px;
		-ms-border-radius: 2px;
		-moz-border-radius: 2px;
		-o-border-radius: 2px;
		-webkit-border-radius: 2px;
}
.contact .envelope {
		position: absolute;
		height: 93px;
		width: 165px;
		left: 50%;
		margin-left: -83px;
		top: 50%;
		margin-top: -50px;
		background: #F9F9F9;
		
		transition: margin-top 300ms;
		-ms-transition: margin-top 300ms;
		-moz-transition: margin-top 300ms;
		-o-transition: margin-top 300ms;
		-webkit-transition: margin-top 300ms;
}
.contact:hover .envelope {
		transition-delay: 150ms;
		-ms-transition-delay: 150ms;
		-moz-transition-delay: 150ms;
		-o-transition-delay: 150ms;
		margin-top: -20px;
}
.contact .envelope .top {
		position: absolute;
		top: -3px;
		left: 0px;
		width: 100%;
		height: 73px;
		z-index: 30;
		overflow: hidden;
						
		transform-origin: top;
		-ms-transform-origin: top;
		-moz-transform-origin: top;
		-o-transform-origin: top;
		-webkit-transform-origin: top;
					
		transition: transform 300ms 150ms, z-index 0ms 150ms, height 300ms 0ms, top 300ms 0ms;
		-ms-transition: -ms-transform 300ms 150ms, z-index 0ms 150ms, height 300ms 0ms, top 300ms 0ms;
		-moz-transition: -moz-transform 300ms 150ms, z-index 0ms 150ms, height 300ms 0ms, top 300ms 0ms;
		-o-transition: -o-transform 300ms 150ms, z-index 0ms 150ms, height 300ms 0ms, top 300ms 0ms;
		-webkit-transition: -webkit-transform 300ms 150ms, z-index 0ms 150ms, height 300ms 0ms, top 300ms 0ms;
}
.contact:hover .envelope .top {
		transition: transform 300ms 0ms, height 300ms 150ms, top 300ms 150ms;
		-ms-transition: -ms-transform 300ms 0ms, height 300ms 150ms, top 300ms 150ms;
		-moz-transition: -moz-transform 300ms 0ms, height 300ms 150ms, top 300ms 150ms;
		-o-transition: -o-transform 300ms 0ms, height 300ms 150ms, top 300ms 150ms;
		-webkit-transition: -webkit-transform 300ms 0ms, height 300ms 150ms, top 300ms 150ms;
		
		height: 10px;
		top: -60px;
  
		transform: rotateX(180deg);
		-ms-transform: rotateX(180deg);
		-moz-transform: rotateX(180deg);
		-o-transform: rotateX(180deg);
		-webkit-transform: rotateX(180deg);
}
.contact .envelope .outer {
		position: absolute;
		bottom: 0px;
		left: 0px;
		border-left: 83px solid transparent;
		border-right: 82px solid transparent;
		border-top: 70px solid #EEE;
}
.contact .envelope .outer .inner {
		position: absolute;
		left: -81px;
		top: -73px;
		border-left: 81px solid transparent;
		border-right: 80px solid transparent;
		border-top: 68px solid #333;
}
.contact .envelope .bottom {
		position: absolute;
		z-index: 20;
		bottom: 0px;
		left: 2px;
		border-left: 81px solid transparent;
		border-right: 80px solid transparent;
		border-bottom: 45px solid #333;
}
.contact .envelope .left {
		position: absolute;
		z-index: 20; top: 0px;
		left: 0px;
		border-left: 81px solid #333;
		border-top: 45px solid transparent;
		border-bottom: 45px solid transparent;
}
.contact .envelope .right {
		position: absolute;
		z-index: 20;
		top: 0px;
		right: 0px;
		border-right: 80px solid #333;
		border-top: 45px solid transparent;
		border-bottom: 45px solid transparent;
}
.contact .envelope .cover {
		position: absolute;
		z-index: 15;
		bottom: 0px;
		left: 0px;
		height: 55%;
		width: 100%;
		background: #EEE;
}
.contact .envelope .paper {
		position: absolute;
		height: 83px;
		padding-top: 10px;
		width: 100%;
		top: 0px;
		left: 0px;
		background: #F9F9F9;
		z-index: 10;
		transition: margin-top 300ms 0ms;
		-ms-transition: margin-top 300ms 0ms;
		-moz-transition: margin-top 300ms 0ms;
		-o-transition: margin-top 300ms 0ms;
		-webkit-transition: margin-top 300ms 0ms;
}
.contact:hover .envelope .paper {
		margin-top: -60px;
		transition: margin-top 300ms 150ms;
		-ms-transition: margin-top 300ms 150ms;
		-moz-transition: margin-top 300ms 150ms;
		-o-transition: margin-top 300ms 150ms;
		-webkit-transition: margin-top 300ms 150ms;
}
.contact .envelope .paper a {
		position: relative;
		display: block;
		font-size: 14px;
		margin: 5px;
		margin-bottom: 0px;
		text-align: center;
		color: #333;
		text-decoration: none;
}

.contact .envelope .paper a {
		color: #333;
  
		transition: color 200ms;
		-ms-transition: color 200ms;
		-moz-transition: color 200ms;
		-o-transition: color 200ms;
		-webkit-transition: color 200ms;
}
.contact .envelope .paper a:hover {
		color: gray;
}
.contact .envelope .paper a.call:hover .i {
		border-color: #DDD;
}
.contact .envelope .paper a.mail .i {
		position: absolute;
		top: 0px;
		left: 17px;
		display: inline-block;
		font-size: 13px;
		font-weight: bold;
}