I have a form that e-mail's me a user's comments.

The strange thing is, is that the "FROM" address is appearing in the e-mail even though I never include it in my mail() statement.

How is that possible?!

PHP Code:
    // Check for Data-Entry Errors.
    
if (empty($errors)){
        
// Form data clean.

        // E-mail Inquiry to Administrator.
        
$to 'debbie@mail.com';
        
$subject $trimmed['subject'];
        
$inquiry $trimmed['inquiry'];
//        $from = $trimmed['senderEmail'];
        
mail($to$subject$inquiry);
    } 

When I get the e-mail in my inbox I see...
Code:
Subject:	Test
From:		user1@user1s-macbook.local
Date:		Mon, Oct 10, 2011 9:31 pm
To:		debbie@mail.com
Sincerely,


Debbie