You're mangling the MAIL function.
mail('me@me.co.uk',$address,$postcode,"From: $name <$tel>");
You should review: PHP.NET
Here's a quick example of mailing the form variables to an email address:
$message = "-----------------------------------------\n";
$message .= "Name = ".$name."\n";
$message .= "Address = ".$address."\n";
$message .= "Postal Code = ".$postcode."\n";
$message .= "Tel = ".$tel."\n";
mail("me@me.co.uk","Form Post",$message, "From: ".$email."\r\n");
In your PHP script, you are inserting a person's telephone number as an email address. You are also adding more parameters than the MAIL() function can handle.
Format: mail("recipient email","your subject","the message","the from address");
Best,
Cent