.mail-sent {
    padding: 15px;
    margin-top: 25px;
    background-color: #66CC77;
    color: #fff;
    border-radius: 5px;
    display: none;
}

.mail-not-sent { 
    background-color: #CC6666;
    padding: 15px;
    margin-top: 25px;
    color: #fff;
    border-radius: 5px;
    display: none;
}