mail function converting hyperlinks to lowercase - why?

[benphp]

$strEvalLink = "<p><a href='http://myserver/evals.php?CLID=3717&INID=93' target='_NewEval'>Please click here to fill out the evaluation for Test</a>.</p><p>Your feedback is important to us.</p><p>Thank You!</p>";

$headers = "Message-ID: <". time() .rand(1,1000). "@".$_SERVER['SERVER_NAME'].">". "\r\n";
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=iso-8859-1" . "\r\n";
$headers .= "$from_email" . "\r\n";
mail($to_email, $strEmailSubject, $strEvalLink, $headers);

The result is an email with the link to:

http://myserver/evals.php?clid=3717&inid=93

I even print the HTML on the page after sending the mail, and the HTML shows the correct Uppercase values.

[benphp]

Strange behavior - so when I hover over the link in the Outlook email, the url shows all lower case. But if I click the link, it goes to the right web page with correct upper/lowercase text.

[TOA]

HTML is not case-sensitive. For example: <A HREF... is the same as <a href ...

[AbraCadaver]

HTML is not case-sensitive. For example: <A HREF... is the same as <a href ...

Variables are case sensitive: CLID=3717&INID=93 is not the same as clid=3717&inid=93

[TOA]

Variables are case sensitive: CLID=3717&INID=93 is not the same as clid=3717&inid=93

I only read his first post and his last comment about the html. Jumped the gun. My bad.