Email from PHP has broken Subject header encoding
email-headers, encoding, mime, php
Solution
Update For a more practical and up-to-date answer, have a look at Palec’s answer.
The specified character encoding in Content-Type does only describe the character encoding of the message body but not the header. You need to use the encoded-word syntax with either the quoted-printable encoding or the Base64 encoding:
encoded-word = "=?" charset "?" encoding "?" encoded-text "?="
You can use `imap_8bit` for the quoted-printable encoding and `base64_encode` for the Base64 encoding:
"Subject: =?UTF-8?B?".base64_encode($subject)."?="
"Subject: =?UTF-8?Q?".imap_8bit($subject)."?="
Problem
My PHP script sends email to users and when the email arrives to their mailboxes, the subject line (`$subject`) has characters like `a^£` added to the end of my subject text. This is obviously and encoding problem. The email message content itself is fine, just the subject line is broken. I have searched all over but can’t find how to encode my subject properly. This is my header. Notice that I’m using `Content-Type` with `charset=utf-8` and `Content-Transfer-Encoding: 8bit`. ``` //set all necessary headers $headers = "From: $sender_name<$from>\n"; $headers .= "Reply-To: $sender_name<$from>\n"; $headers .= "X-Sender: $sender_name<$from>\n"; $headers .= "X-Mailer: PHP4\n"; //mailer $headers .= "X-Priority: 3\n"; //1 UrgentMessage, 3 Normal $headers .= "MIME-Version: 1.0\n"; $headers .= "X-MSMail-Priority: High\n"; $headers .= "Importance: 3\n"; $headers .= "Date: $date\n"; $headers .= "Delivered-to: $to\n"; $headers .= "Return-Path: $sender_name<$from>\n"; $headers .= "Envelope-from: $sender_name<$from>\n"; $headers .= "Content-Transfer-Encoding: 8bit\n"; $headers .= "Content-Type: text/plain; charset=UTF-8\n"; ```