The "EMC" stuff was just a quick way of me putting a message together - it's cleaner that the multiline double quotes in your example IMHO - that's all.

A "quick" answer would be for you to simple add
$headers .= "Content-type: text/html\n";
just before the mail line and that should get you sorted. But there's a lot to PHP and if this stuff is all pretty new, some of the tutorials that are around should help. Learning the whole thing by "question / answer" on a forum isn't practical - though it's a darned good way of sorting out issues that arise.