The funny thing is it did work for one evening. I contacted my host, and they are saying there's no reason it should not be working. I have also attempted to test it in Firebug, but it seemed to be sending. And I specifically put the email address (hosted in my domain) on my email safe list, so that is not the culprit either.

Would anyone here take a look at it for me? I'd be so grateful.

In the header I have:

<script type="text/javascript"> 
$(document).ready(function() { 
var options = { 
target:        '#alert'
}; 
$('#contactForm').ajaxForm(options); 
}); 

$.fn.clearForm = function() {
  return this.each(function() {
 var type = this.type, tag = this.tagName.toLowerCase();
 if (tag == 'form')
   return $(':input',this).clearForm();
  if (type == 'text' || type == 'password' || tag == 'textarea')
   this.value = '';
 else if (type == 'checkbox' || type == 'radio')
   this.checked = false;
 else if (tag == 'select')
   this.selectedIndex = -1;
  });
};

</script>

Here is the actual form:

<form id="contactForm" method="post" action="sendmail.php"> 

<fieldset> 

<p>Email Me</p> 
<div id="fieldset_container"> 
<label for="name">Your Name:</label> 
<input type="text" name="name" id="name" /><br /><br /> 

<label for="email">Email:</label> 
<input type="text" name="email" id="email" /><br /><br /> 

<span style="display:none;"> 
<label for="last">Honeypot:</label> 
<input type="text" name="last" value="" id="last" /> 
</span><br /><br /> 

<label for="message">Comments &amp; Inquiries:</label> 
<textarea name="message" id="message" cols="" rows=""></textarea><br/> 
</div> 
<div id="submit_button"> 
<input type="submit" name="submit" id="submit" value="Send It" /> 
</div> 
</fieldset> 

</form> 

<div class="message"><div id="alert"></div></div>

Here is the code from my validating page, sendmail.php:

<?php

//        Who you want to recieve the emails from the form. (Hint: generally you.)
$sendto = '[email protected]';

//        The subject you'll see in your inbox
$subject = 'SH Contact Form';

//        Message for the user when he/she doesn't fill in the form correctly.
$errormessage = 'There seems to have been a problem. May I suggest...';

//        Message for the user when he/she fills in the form correctly.
$thanks = "Thanks for the email!";

//        Message for the bot when it fills in in at all.
$honeypot = "You filled in the honeypot! If you're human, try again!";

//        Various messages displayed when the fields are empty.
$emptyname =  'Entering your name?';
$emptyemail = 'Entering your email address?';
$emptymessage = 'Entering a message?';

//       Various messages displayed when the fields are incorrectly formatted.
$alertname =  'Entering your name using only the standard alphabet?';
$alertemail = 'Entering your email in this format: <i>[email protected]</i>?';
$alertmessage = "Making sure you aren't using any parenthesis or other escaping                    characters in the message? Most URLS are fine though!";


//Setting used variables.
$alert = '';
$pass = 0;

// Sanitizing the data, kind of done via error messages first. Twice is better!  ;-)
function clean_var($variable) {
    $variable = strip_tags(stripslashes(trim(rtrim($variable))));
  return $variable;
}

//The first if for honeypot.
if ( empty($_REQUEST['last']) ) {

 // A bunch of if's for all the fields and the error messages.
if ( empty($_REQUEST['name']) ) {
 $pass = 1;
 $alert .= "<li>" . $emptyname . "</li>";
} elseif ( ereg( "[][{}()*+?.\\^$|]", $_REQUEST['name'] ) ) {
 $pass = 1;
 $alert .= "<li>" . $alertname . "</li>";
}
if ( empty($_REQUEST['email']) ) {
 $pass = 1;
 $alert .= "<li>" . $emptyemail . "</li>";
} elseif ( !eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,3})$", $_REQUEST['email']) ) {
 $pass = 1;
 $alert .= "<li>" . $alertemail . "</li>";
}
if ( empty($_REQUEST['message']) ) {
 $pass = 1;
 $alert .= "<li>" . $emptymessage . "</li>";
} elseif ( ereg( "[][{}()*+?\\^$|]", $_REQUEST['message'] ) ) {
 $pass = 1;
 $alert .= "<li>" . $alertmessage . "</li>";
}

 //If the user err'd, print the error messages.
 if ( $pass==1 ) {

  //This first line is for ajax/javascript, comment it or delete it if this isn't your cup o' tea.
 echo "<script>$(\".message\").hide(\"slow\").show(\"slow\"); </script>";
 echo "<b>" . $errormessage . "</b>";
 echo "<ul>";
 echo $alert;
 echo "</ul>";

 // If the user didn't err and there is in fact a message, time to email it.
 } elseif (isset($_REQUEST['message'])) {

  //Construct the message.
     $message = "From: " . clean_var($_REQUEST['name']) . "\n";
  $message .= "Email: " . clean_var($_REQUEST['email']) . "\n";
     $message .= "Message: \n" . clean_var($_REQUEST['message']);
     $header = 'From:'. clean_var($_REQUEST['email']);

//Mail the message - for production
  mail($sendto, $subject, $message, $header, "[email protected]");
//This is for javascript, 
  echo "<script>$(\".message\").hide(\"slow\").show(\"slow\").animate({opacity: 1.0}, 4000).hide(\"slow\"); $(':input').clearForm() </script>";
  echo $thanks;
  die();

//Echo the email message - for development
  echo "<br/><br/>" . $message;

 }

//If honeypot is filled, trigger the message that bot likely won't see.
} else {
 echo "<script>$(\".message\").hide(\"slow\").show(\"slow\"); </script>";
 echo $honeypot;
}
?>