Pass a fourth parameter to the mail() function with the header information.

<?php
$to = "jane@example.com";
$subject = "Hello World!";
$body = "This will be sent from email-addr@example.com";
$headers = "From: email-addr@example.com\r\nX-Mailer: php";
mail($to, $subject, $body, $headers);

Quick and dirty way to grab the users status messages without having to go through the twitter api (not having to authenticate that is). You can grab the RSS feed and indicate the number of statuses returned with the count param. I wrote this function for my blog in PHP. It uses the curl extension so if it’s not installed type

apt-get install php5-curl

Otherwise you’ll have to use the fsockopen function. Then it’s just a matter of parsing the XML and getting at what data you want. I just want one status so I’m accessing the element directly, rather than looping over the returned data set.

<php
function latest_twitter_status_message(){
        // grab the rss feed link from some user, like me and indicate the count in the url
	$host = "http://twitter.com/statuses/user_timeline/11036982.rss?count=1";
	// using curl
	$ch = curl_init($host);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($ch, CURLOPT_HEADER, 0);
	$data = curl_exec($ch);
	curl_close($ch);
	$doc = new SimpleXmlElement($data, LIBXML_NOCDATA);
	return "{$doc->channel->item[0]->description}";
}