Well, first you have to use quotes. Second, you need a semicolon. Third, you didn't close your second php tag correctly. Lastly, he needs the code in a variable, so it can be put into an email.
Here is the correct code:
<?php
$email = 'vincery@excite.com';
$message = <<<EOS
<html>
<head>
<title>Membership Details</title>
</head>
<body>
<p>You have successfully joined membership.</p>
<p>Your username is: $email<br />
Your password is: <strong>password</strong></p>
</body>
</html>
EOS;
?>
Don't just copy and paste this code. "EOS;" probably has a space after the semicolon. Once you paste it into your code, remove all spaces after "EOS;" and you should be ok.
Rapidex, don't be so quick to give up. And always look over code that someone gives you closely. You don't know if there are going to be mistakes, and you are ultimately responsible for your own code.