Lately, we have transitioned our environment over to use UTF-8 encoding. Everything seemed to be working perfectly. Pages were being served up correctly in UTF-8 and email sent with PHP's mail() function were also being sent with (in our case) French characters appearing properly.
This morning, I started substituting non-multi-byte string functions (e.g., strlen(), mail()) with their multi-byte counterpart (e.g., mb_strlen(), mb_send_mail()) and it appears to be working as expected in all cases, except for mb_send_mail(), where French characters appear as question marks. Oddly, they appear correctly when using mail(). I also have the charset set to utf-8 in the email's headers in both cases, and checking it in my email client confirms that it is sent as such.
I should add that I am not using the Function Overloading feature, because I was concerned it would interfere with third-party extensions we are using, which is why I have chosen to replace the functions manually.
EDIT
These lines were modified/added in php.ini:
default_charset = "utf-8"
mbstring.language=Neutral
mbstring.internal_encoding=utf-8
mbstring.http_input=UTF-8
mbstring.http_output=UTF-8
mbstring.encoding_translation=On
My PHP files are also all saved in UTF-8 encoding, without BOM.
The code when calling the mb_send_mail() function looks like this:
$to = "person@email.com";
$subject = "Assigné";
$body = "La demande suivante vous a été assigné : "
$headers .= 'From: ' . $from . "
";
$headers .= 'MIME-Version: 1.0' . "
";
$headers .= 'Content-Type: text/html; charset="utf-8"' . "
";
$headers .= 'Content-Transfer-Encoding: quoted-printable' . "
";
if (!(@mb_send_mail($to, $subject, $body, $headers))) {
//Error message
}
As indicated in my original post, when using the mb_send_mail() function, all my e acute (é) characters, including the email's subject and bosy, appear as question marks (?), but when using the mail() function, they appear as intended.
Keep the mail() function it works better as far as I have noticed.
See PHP manual for mb_send_mail() others recommend it to.