Webmasters at quality sites won't even see your message. Many of them, like me, have their email set to automatically trash any message that smacks of "link exchange", "trade links", "reciprocal link", etc. And if the first thing you thought of was how to get past the email filter, then you're MISSING THE POINT. If you get past the filter then congratulations, now the webmaster will just trash your request manually instead of automatically. You haven't gained anything but to waste someone else's time who didn't want your message in the first place.