buzztone on "[Plugin: Contact Form 7] The email form square suddenly disappeared"

Use Firebug or Chrome Dev Tools to solve problems like this.

To fix you need to edit the CSS style sheets used by your WordPress theme.

See Styling Contact Form for a general explanation of styling CF7 forms using CSS. If you are not familiar with CSS, this page also includes some links to where you can learn CSS.

In your case HTML form element input[type="email"] is not defined in your themes style.css file - http://www.jeteran.com/wp-content/themes/perfect/style.css

CURRENT:
textarea, input[type="text"],
 input[type="password"],
 select {
    background: none repeat scroll 0 0 #FFFFFF;
    border: 1px solid #D7D7D7;
    color: #747474;
}

CHANGE TO:
textarea, input[type="text"],
 input[type="password"],
 input[type="email"],  /* ADD THIS LINE */
 select {
    background: none repeat scroll 0 0 #FFFFFF;
    border: 1px solid #D7D7D7;
    color: #747474;
}