If you have sent e-mails in a different language than English or using characters outside the ASCII range you have probably already used UTF to send them.
Specifying the use of UTF-8 in the body of an e-mail is very similar to doing it for a HTTP response. You can specify the content-type in an e-mail header like this:
Content-Type: text/plain; charset=utf-8
But there is catch. The subject line of an e-mail is a header by itself, and headers must contain only ASCII characters. Happily, there is a work around. RFC 1342 is a recommendation that provides a way to represent non ASCII characters inside e-mail headers in a way that won’t confuse e-mail servers.
To encode a header using this technique you must use this format:
And this is an example of its use:
The encoding must be either B or Q, these mean base 64 and quoted-printable respectively. You can read the RFC 1342 document for more information about how they work.
Here is a snippet of how to use php’s mail function to send an e-mail using UTF-8 in the subject and content:
$to = 'email@example.com'; $subject = 'Subject with non ASCII ó¿¡á'; $message = 'Message with non ASCII ó¿¡á'; $headers = 'From: firstname.lastname@example.org'."\r\n" .'Content-Type: text/plain; charset=utf-8'."\r\n"; mail($to, '=?utf-8?B?'.base64_encode($subject).'?=', $message, $headers);