Sending emails in Japanese language was a challenge for me. Any email, which had a subject in Japanese language failed and was not being sent at all. I tried encoding the email subject, but nothing worked. I tweaked things until i found a solution. I then re-defined the wordpress core wp_mail() function to allow sending emails with Japanese language in subject. My solution is given below (see modifications from line 337 and onwards in code below):
//wp_mail redefined, to send japanese subject line in emails.
function wp_mail( $to, $subject, $message, $headers = '', $attachments = array() ) {
// Compact the input, apply the filters, and extract them back out
/**
* Filter the wp_mail() arguments.
*
* @since 2.2.0
*
* @param array $args A compacted array of wp_mail() arguments, including the "to" email,
* subject, message, headers, and attachments values.
*/
$atts = apply_filters( 'wp_mail', compact( 'to', 'subject', 'message', 'headers', 'attachments' ) );
if ( isset( $atts['to'] ) ) {
$to = $atts['to'];
}
if ( isset( $atts['subject'] ) ) {
$subject = $atts['subject'];
}
if ( isset( $atts['message'] ) ) {
$message = $atts['message'];
}
if ( isset( $atts['headers'] ) ) {
$headers = $atts['headers'];
}
if ( isset( $atts['attachments'] ) ) {
$attachments = $atts['attachments'];
}
if ( ! is_array( $attachments ) ) {
$attachments = explode( "\n", str_replace( "\r\n", "\n", $attachments ) );
}
global $phpmailer;
// (Re)create it, if it's gone missing
if ( !is_object( $phpmailer ) || !is_a( $phpmailer, 'PHPMailer' ) ) {
require_once ABSPATH . WPINC . '/class-phpmailer.php';
require_once ABSPATH . WPINC . '/class-smtp.php';
$phpmailer = new PHPMailer( true );
}
// Headers
if ( empty( $headers ) ) {
$headers = array();
} else {
if ( !is_array( $headers ) ) {
// Explode the headers out, so this function can take both
// string headers and an array of headers.
$tempheaders = explode( "\n", str_replace( "\r\n", "\n", $headers ) );
} else {
$tempheaders = $headers;
}
$headers = array();
$cc = array();
$bcc = array();
// If it's actually got contents
if ( !empty( $tempheaders ) ) {
// Iterate through the raw headers
foreach ( (array) $tempheaders as $header ) {
if ( strpos($header, ':') === false ) {
if ( false !== stripos( $header, 'boundary=' ) ) {
$parts = preg_split('/boundary=/i', trim( $header ) );
$boundary = trim( str_replace( array( "'", '"' ), '', $parts[1] ) );
}
continue;
}
// Explode them out
list( $name, $content ) = explode( ':', trim( $header ), 2 );
// Cleanup crew
$name = trim( $name );
$content = trim( $content );
switch ( strtolower( $name ) ) {
// Mainly for legacy -- process a From: header if it's there
case 'from':
if ( strpos($content, '<' ) !== false ) {
// So... making my life hard again?
$from_name = substr( $content, 0, strpos( $content, '<' ) - 1 );
$from_name = str_replace( '"', '', $from_name );
$from_name = trim( $from_name );
$from_email = substr( $content, strpos( $content, '<' ) + 1 ); $from_email = str_replace( '>', '', $from_email );
$from_email = trim( $from_email );
} else {
$from_email = trim( $content );
}
break;
case 'content-type':
if ( strpos( $content, ';' ) !== false ) {
list( $type, $charset ) = explode( ';', $content );
$content_type = trim( $type );
if ( false !== stripos( $charset, 'charset=' ) ) {
$charset = trim( str_replace( array( 'charset=', '"' ), '', $charset ) );
} elseif ( false !== stripos( $charset, 'boundary=' ) ) {
$boundary = trim( str_replace( array( 'BOUNDARY=', 'boundary=', '"' ), '', $charset ) );
$charset = '';
}
} else {
$content_type = trim( $content );
}
break;
case 'cc':
$cc = array_merge( (array) $cc, explode( ',', $content ) );
break;
case 'bcc':
$bcc = array_merge( (array) $bcc, explode( ',', $content ) );
break;
default:
// Add it to our grand headers array
$headers[trim( $name )] = trim( $content );
break;
}
}
}
}
// Empty out the values that may be set
$phpmailer->ClearAllRecipients();
$phpmailer->ClearAttachments();
$phpmailer->ClearCustomHeaders();
$phpmailer->ClearReplyTos();
// From email and name
// If we don't have a name from the input headers
if ( !isset( $from_name ) )
$from_name = 'WordPress';
/* If we don't have an email from the input headers default to wordpress@$sitename
* Some hosts will block outgoing mail from this address if it doesn't exist but
* there's no easy alternative. Defaulting to admin_email might appear to be another
* option but some hosts may refuse to relay mail from an unknown domain. See
* https://core.trac.wordpress.org/ticket/5007.
*/
if ( !isset( $from_email ) ) {
// Get the site domain and get rid of www.
$sitename = strtolower( $_SERVER['SERVER_NAME'] );
if ( substr( $sitename, 0, 4 ) == 'www.' ) {
$sitename = substr( $sitename, 4 );
}
$from_email = 'wordpress@' . $sitename;
}
/**
* Filter the email address to send from.
*
* @since 2.2.0
*
* @param string $from_email Email address to send from.
*/
$phpmailer->From = apply_filters( 'wp_mail_from', $from_email );
/**
* Filter the name to associate with the "from" email address.
*
* @since 2.3.0
*
* @param string $from_name Name associated with the "from" email address.
*/
$phpmailer->FromName = apply_filters( 'wp_mail_from_name', $from_name );
// Set destination addresses
if ( !is_array( $to ) )
$to = explode( ',', $to );
foreach ( (array) $to as $recipient ) {
try {
// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
$recipient_name = '';
if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
if ( count( $matches ) == 3 ) {
$recipient_name = $matches[1];
$recipient = $matches[2];
}
}
$phpmailer->AddAddress( $recipient, $recipient_name);
} catch ( phpmailerException $e ) {
continue;
}
}
// Set mail's subject and body
$phpmailer->Subject = $subject;
// Convert Japanese subject to ISO-2022-JP (JIS is essentially ISO-2022-JP)
$subject = mb_convert_encoding ($subject, "JIS", "AUTO");
// Now, base64 encode the subject
$subject = base64_encode ($subject);
// Add the encoding markers to the subject
$subject = "=?iso-2022-jp?B?" . $subject . "?=";
// Now, $subject can be placed as-is into the raw mail header.
$phpmailer->Subject = $subject;
$phpmailer->Body = $message;
// Add any CC and BCC recipients
if ( !empty( $cc ) ) {
foreach ( (array) $cc as $recipient ) {
try {
// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
$recipient_name = '';
if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
if ( count( $matches ) == 3 ) {
$recipient_name = $matches[1];
$recipient = $matches[2];
}
}
$phpmailer->AddCc( $recipient, $recipient_name );
} catch ( phpmailerException $e ) {
continue;
}
}
}
if ( !empty( $bcc ) ) {
foreach ( (array) $bcc as $recipient) {
try {
// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
$recipient_name = '';
if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
if ( count( $matches ) == 3 ) {
$recipient_name = $matches[1];
$recipient = $matches[2];
}
}
$phpmailer->AddBcc( $recipient, $recipient_name );
} catch ( phpmailerException $e ) {
continue;
}
}
}
// Set to use PHP's mail()
$phpmailer->IsMail();
// Set Content-Type and charset
// If we don't have a content-type from the input headers
if ( !isset( $content_type ) )
$content_type = 'text/html';
/**
* Filter the wp_mail() content type.
*
* @since 2.3.0
*
* @param string $content_type Default wp_mail() content type.
*/
$content_type = apply_filters( 'wp_mail_content_type', $content_type );
$phpmailer->ContentType = "text/plain";
// Set whether it's plaintext, depending on $content_type
if ( 'text/html' == $content_type )
$phpmailer->IsHTML( true );
// If we don't have a charset from the input headers
if ( !isset( $charset ) )
$charset = get_bloginfo( 'charset' );
$charset ='UTF-8';
// Set the content-type and charset
/**
* Filter the default wp_mail() charset.
*
* @since 2.3.0
*
* @param string $charset Default email charset.
*/
$phpmailer->CharSet = apply_filters( 'wp_mail_charset', $charset );
$phpmailer->CharSet ='UTF-8';
// Set custom headers
if ( !empty( $headers ) ) {
foreach( (array) $headers as $name => $content ) {
$phpmailer->AddCustomHeader( sprintf( '%1$s: %2$s', $name, $content ) );
}
if ( false !== stripos( $content_type, 'multipart' ) && ! empty($boundary) )
$phpmailer->AddCustomHeader( sprintf( "Content-Type: %s;\n\t boundary=\"%s\"", $content_type, $boundary ) );
}
if ( !empty( $attachments ) ) {
foreach ( $attachments as $attachment ) {
try {
$phpmailer->AddAttachment($attachment);
} catch ( phpmailerException $e ) {
continue;
}
}
}
/**
* Fires after PHPMailer is initialized.
*
* @since 2.2.0
*
* @param PHPMailer &$phpmailer The PHPMailer instance, passed by reference.
*/
$phpmailer->ContentType = "text/plain";
do_action_ref_array( 'phpmailer_init', array( &$phpmailer ) );
// Send!
try {
return $phpmailer->Send();
} catch ( phpmailerException $e ) {
return false;
}
}
Happy coding!
