Signing PHP emails on shared hosting - digital-signature

Question

I am on a shared hosting plan, and when I send emails with PHP, email clients (like Gmail) will add a little via bit to my from field, with my host's domain in there.
So instead of my emails being just from my domain:
From: me#mydomain.com
It's from two domains:
From: me#mydomain.com via host13.myhost.com
Clearly, this is confusing to people receiving email and is poor branding. Since I'm on a shared hosting plan, I don't think I'm likely to have access to the configurations settings of PHP or whatever it uses to mail. Is it possible for me to digitally sign my PHP emails, or is this not possible on shared hosting?
Here is what I'm doing now:
$header = "From: me#mydomain.com";
mail("you#yourdomain.com", "subject", "body", $header);

Answer 1

You can try this, you need to download the PHP Mailer class from Here and your code will be like this:
<?php
include "PHP MAILER CLASS";
$mail = new PHPMailer(true); // the true param means it will throw exceptions on errors, which we need to catch
$mail->IsSMTP(); // telling the class to use SMTP
try {
//$mail->SMTPDebug = 1; // enables SMTP debug information (for testing)
$mail->SMTPAuth = true; // enable SMTP authentication
$mail->SMTPSecure = "ssl"; // sets the prefix to the servier
$mail->Host = "smtp.gmail.com"; // sets GMAIL as the SMTP server
$mail->Port = 465; // set the SMTP port for the GMAIL server
$mail->Username = "example#gmail.com"; // GMAIL username
$mail->Password = "password"; // GMAIL password
$mail->AddAddress("Reciever Email", "Reciever Name");
$mail->SetFrom('Sender Email', 'Sender Name');
$mail->Subject = "Subject";
$mail->AltBody = 'To view the message, please use an HTML compatible email viewer!'; // optional - MsgHTML will create an alternate automatically
$mail->MsgHTML("Message Body");
$mail->Send();
} catch (phpmailerException $e) {
$e->errorMessage(); //Pretty error messages from PHPMailer
} catch (Exception $e) {
$e->getMessage(); //Boring error messages from anything else!
}
?>

Answer 2

The default mail function is at the mercy of your server setup and rarely looks like regular mail to the reciever. You should use a library either SwitfMailer or pear MAIL that can send the mail through your own mail server via SMTP. You can use your normal email account or setup a new one for your web service.