用php发送邮件不会给出预期的结果

Question

I have this form which I used all over my site and it's working fine but when I used extra data into my content it stop sending even it don't display the message that there was an error or any other message

this is the form it self

<form action="" method="post">
<table width="683" border="0" cellspacing="0" cellpadding="10">
  <tr>
    <td width="96">Full Name</td>
    <td colspan="4"><label for="textfield"></label>
    <input type="text" name="fname" id="fname" /></td>
  </tr>
  <tr>
    <td>E-mail</td>
    <td colspan="4"><input type="text" name="email" id="email" /></td>
  </tr>
  <tr>
    <td>Company</td>
    <td colspan="4"><input type="text" name="company" id="company" /></td>
  </tr>
  <tr>
    <td colspan="5">How do you rate our services and products:</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td width="120"><input type="radio" name="s_rate" id="Poor" value="Poor" />
Poor </td>
    <td width="120"><input type="radio" name="s_rate" id="Good" value="Good" />
Good </td>
    <td width="120"><input type="radio" name="s_rate" id="Very_Good" value="Very Good" />
Very Good </td>
    <td width="127"><input type="radio" name="s_rate" id="Excellent" value="Excellent" />
Excellent</td>
  </tr>
  <tr>
    <td colspan="5"><p>How did you know about us?</p></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td><input type="radio" name="know" id="Google" value="Google" />
Google</td>
    <td><input type="radio" name="know" id="E_mail" value="E-mail" />
E-mail</td>
    <td><input type="radio" name="know" id="A_friend" value="A friend" />
A friend</td>
    <td><input type="radio" name="know" id="Social_Media" value="Social Media" />
Social Media</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td colspan="2"><input type="radio" name="know" id="advertisement" value="An advertisement at a  web site" />
An advertisement at a  web site</td>
    <td colspan="2"><input type="radio" name="know" id="Old_customer" value="I am an old customer" />
    I am an old customer</td>
  </tr>
  <tr>
    <td colspan="5">Would you recommend us to your friends and colleagues:</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td><input type="radio" name="recommend" id="Yes" value="Yes" />
Yes </td>
    <td><input type="radio" name="recommend" id="No" value="No" />
No</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td colspan="5">Do you have any suggestions to make us improve our services?</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td colspan="4">
    <textarea name="message" id="message" cols="45" rows="5"></textarea></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td><input type="submit" name="Submit" id="button" value="Submit" /></td>
  </tr>
</table>
</form>

and this is my php code

<?php
      if(isset($_POST['submit'])){
          echo "done";

            $name = $_POST['fname'];
            $email = $_POST['email'];
            $company = $_POST['company'];
            $s_rate = $_POST['s_rate'];
            $know = $_POST['know'];
            $recommend = $_POST['recommend'];
            $message = $_POST['message'];

            $recipient = '[e-mail]'; 
            $subject="feedback"; 

            $content = "New feedback 
 From: ".$name.",
 Email: ".$email.", 
 Company: ".$company.", 
 He rate our services as: ".$s_rate.", 
 He know about us from: ".$know.", 
 Would he recommend us to his friends: ".$recommend.", 
 He's suggestions was: ".$message; 
            $headers = 'From: [e-mail]' . "
" .
    'Reply-To: [e-mail]' . "
" .
    'X-Mailer: PHP/' . phpversion();
    $retval=mail($recipient, $message, $content, $headers);

   if($retval==true)
   {
      echo "<span style='color:green; font-size:16px; margin-left:35px; font-family:Arial, Helvetica, sans-serif;'>Message sent successfully...</span>";
   }
   else
   {
      echo "<span style='color:red; font-size:16px; margin-left:35px; font-family:Arial, Helvetica, sans-serif;'>Message could not be sent...</span>";
   }
}
?>

now when I submit the form I return to the same page without any results the mail not sending anything and not even message.

the content is

$content = "New feedback 
 From: ".$name.",
 Email: ".$email.", 
 Company: "
.$company.", 
 He rate our services as: ".$s_rate.", 
 He know about us from: "
.$know.", 
 Would he recommend us to his friends: "
.$recommend.", 
 He's suggestions was: ".$message;

does it make any different that I put many data in it.

Thanks and regards.

Answer 1

You have

<input type="submit" name="Submit" id="button" value="Submit" />

but check for submission using

isset($_POST['submit'])

You use upper case Submit in the name-attribute of the button, but check for lower case submit in the PHP script.