转载链接：http://code.web-max.ca/misc_htmlemail.php
发送一个HTML格式的电子邮件，主要在邮件的头信息中定义邮件正文的类型：
Content-Type:text/html;charset="utf-8"。
示例：
<?php// Example $HTML = "<b>This is a test</b>";
$from = "test@test.com";
$to = "this@that.com";
$subject = "I'm sending a test HTML email";sendHTMLemail($HTML,$from,$to,$subject);function sendHTMLemail($HTML,$from,$to,$subject)
{
// First we have to build our email headers
// Set out "from" address$headers = "From: $from\r\n"; // Now we specify our MIME version$headers .= "MIME-Version: 1.0\r\n"; // Create a boundary so we know where to look for
// the start of the data$boundary = uniqid("HTMLEMAIL"); // First we be nice and send a non-html version of our email$headers .= "Content-Type: multipart/alternative;"."boundary = $boundary\r\n\r\n"; $headers .= "This is a MIME encoded message.\r\n\r\n"; $headers .= "--$boundary\r\n"."Content-Type: text/plain; charset=ISO-8859-1\r\n"."Content-Transfer-Encoding: base64\r\n\r\n"; $headers .= chunk_split(base64_encode(strip_tags($HTML))); // Now we attach the HTML version$headers .= "--$boundary\r\n"."Content-Type: text/html; charset=ISO-8859-1\r\n"."Content-Transfer-Encoding: base64\r\n\r\n"; $headers .= chunk_split(base64_encode($HTML)); // And then send the email ....mail($to,$subject,"",$headers);}?> 
)
