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(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)



    string $to,
    string $subject,
    string $message,
    array|string $additional_headers = [],
    ?string $additional_params = null
): bool

发送邮件。邮件头和内容根据 mb_language() 设置来转换编码。 这是 mail() 的一个包装器函数,所以详情参见 mail()



被发送到该邮件地址。可通过逗号分隔地址的 to 来指定多个收件人。 该参数不会被自动编码。






要插入到电子邮件标头末尾的 stringarray

这通常用于添加额外的标头(发件人、抄送和密件抄送)。多个额外的标头应该用 CRLF(\r\n)分隔。验证参数不会被攻击者注入不需要的标头。

如果传递 array,则其键是标头名称,其值是相应的标头值。


发送邮件时,邮件必须包含 From 标头。这可以使用 additional_headers 参数设置,或者可以在 php.ini 中设置默认值。

如果不这样做,将导致类似于 Warning: mail(): "sendmail_from" not set in php.ini or custom "From:" header missing 的错误消息。From 标头还设置了 Windows 下的 Return-Path


如果未收到消息,请尝试仅使用 LF(\n)。一些 Unix 邮件传输代理(最著名的是 » qmail)自动将 LF 替换为 CRLF(如果使用 CRLF,这会导致两个 CR)。这应该是最后的手段,因为它不符合 » RFC 2822


additional_params 是一个 MTA 命令行参数。在使用 sendmail 时对设置正确的返回路径头很有帮助。

该参数由 escapeshellcmd() 内部转义以防止命令执行。escapeshellcmd() 阻止命令执行,但允许添加额外的参数。出于安全原因,应该验证此参数。

Since escapeshellcmd() is applied automatically, some characters that are allowed as email addresses by internet RFCs cannot be used. Programs that are required to use these characters mail() cannot be used.

Web 服务器运行的用户应作为受信任的用户添加到 sendmail 配置中,以防止在使用此方法设置信封发件人(-f)时将“X-Warning”标头添加到邮件中。对于 sendmail 用户,此文件为 /etc/mail/trusted-users


成功时返回 true, 或者在失败时返回 false


版本 说明
8.0.0 additional_params 现在可为 null。
7.2.0 additional_headers 参数现在也接受 array


add a note

User Contributed Notes 16 notes

gordon at kanazawa-gu dot ac dot jp
21 years ago
If your server doesn't have mb_send_mail() enabled but you want to use non-ascii (multi-byte) chars in an email's subject or name headers, you can use something like the following:

$charset = "iso-2202-jp"; // japanese
$to = encode("japanese name 01", $charset) . " <>";
$from = encode("japanese name 02", $charset) . " <>";
$subject = encode("japanese text", $charset);
$message = "does not need to be encoded";
mail($to, $subject, $message, $from);

function encode($in_str, $charset) {
$out_str = $in_str;
if ($out_str && $charset) {

// define start delimimter, end delimiter and spacer
$end = "?=";
$start = "=?" . $charset . "?B?";
$spacer = $end . "\r\n " . $start;

// determine length of encoded text within chunks
// and ensure length is even
$length = 75 - strlen($start) - strlen($end);
$length = floor($length/2) * 2;

// encode the string and split it into chunks
// with spacers after each chunk
$out_str = base64_encode($out_str);
$out_str = chunk_split($out_str, $length, $spacer);

// remove trailing spacer and
// add start and end delimiters
$spacer = preg_quote($spacer);
$out_str = preg_replace("/" . $spacer . "$/", "", $out_str);
$out_str = $start . $out_str . $end;
return $out_str;
// for details on Message Header Extensions
// for Non-ASCII Text see ...
dynamis at skillup dot jp
20 years ago
# self-fix...
I posted "encode_mimeheader" workaround on the day before. But I found that the code depends on platforms. :(

In some platforms, hedders(after the header splited into two or more lines) will appear in the body content.
The cause is that 'there are some platforms where the translation from \n to \r\n is apparently done for you'.
# See the post by "leon at ietsmet dot nl" about mail function (23-Apr-2003).

Now, all you have to do is just changing the glue string from "\r\n " to "\n ".

function encode_mimeheader($str, $indent = 0, $encoding = 'utf-8', $mail_encoding = 'iso-2022-jp')
..... lefted out (all same).....
$str = join("\r\n ", $lines); // RFC 2047,822 say newline must be ^\r\n, not only\n
return $str;

should be below in some platform...

function encode_mimeheader($str, $indent = 0, $encoding = 'utf-8', $mail_encoding = 'iso-2022-jp')
..... lefted out (all same).....
$str = join("\n ", $lines);
// Though RFC 2047,822 say newline must be \r\n, not only \n,
// in my platform, auto replacement will be done (accepts \n and \n\r\n -> \n\n)...
return $str;

# notice: In both code, 1 space after newline is essential (gule str is *not* only "\r\n" nor "\n").
# This space is ignored only between encoded-words.

c.f. about efficiency

Thinking about efficiency, my encode_mimeheader may have to determine where to split string into lines without mb_encode_mimeheader in the determining loop. But that loop will be repeated only one or a few times and this function will be usually used against not so long string. So, this loss is not critical in most case.
If you use only one encoding, you can easily check ascii or multi-byte char one by one accoding to the definition of the encoding and determining splitting point (this is far faster), but when you have to handle all encoding that is not so easy. At least, I don't want to touch. :p
To accept *any* encoding (encoding name will be passed as argument), you can use this code. This is because I post non-efficient code like this.
# Though I'm not sure whether the code actually work well with all encoding...
RE: N03L in Japan
21 years ago
I have to use Japanese hankaku (single byte kana in (S)JIS) in mail subject and message,
so I tried the way that NO3L in Japan said, but I found there's a big problem.
In that way, mb_encode_mimeheader drop escape sequence from the head of encoded string from second line.
if you use long letter in subject, and if it includes multi byte string, It must crashed.
Therefore, if you want to use Japanese hankaku in mail subject, you might try like this.
Encoded subject letters in one line is not just 76 letters, so it is not based on RFC, but it work.

$intSubjectLength = mb_strlen($strSubject);
$intSeparateLength = 10;
for ($i=0; $i<ceil($intSubjectLength / $intSeparateLength); $i++) {
$arrSeparatedSubject[$i] = mb_substr($strSubject, $intIndex, $intSeparateLength);
$arrSeparatedSubject[$i] = mb_encode_mimeheader(mb_convert_encoding($arrSeparatedSubject[$i], "JIS", "EUC-JP"));
$intIndex = $intIndex + $intSeparateLength;
$strSubject = join("\n ", $arrSeparatedSubject);
bredfern at calarts dot edu
19 years ago
Make sure that if you're using a form to type in the mail, that your form page has the right encoding, like if I want to send out a japanese email, by filling out a form, the form page needs this in the header:
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=SHIFT-JIS">
Sohel Taslim
16 years ago
Easy and simple....
Send an email with Japanese contain.


* @name : sendMail
* @author Taslim Mazumder Sohel
* Function for sending email
*with Japanese Email Body, Subject, Sender Name.
* @param String $to : Receiver mail address.
* @param String $subject : email subject.
* @param int $body : mail body text.
* @param array $from_email : Sender mail address.
* @param array $from_name : Sender Name.
function sendMail($to, $subject, $body, $from_email,$from_name)
$headers = "MIME-Version: 1.0 \n" ;
$headers .= "From: " .
"".mb_encode_mimeheader (mb_convert_encoding($from_name,"ISO-2022-JP","AUTO")) ."" .
"<".$from_email."> \n";
$headers .= "Reply-To: " .
"".mb_encode_mimeheader (mb_convert_encoding($from_name,"ISO-2022-JP","AUTO")) ."" .
"<".$from_email."> \n";

$headers .= "Content-Type: text/plain;charset=ISO-2022-JP \n";

/* Convert body to same encoding as stated
in Content-Type header above */

$body = mb_convert_encoding($body, "ISO-2022-JP","AUTO");

/* Mail, optional paramiters. */
$sendmail_params = "-f$from_email";

$subject = mb_convert_encoding($subject, "ISO-2022-JP","AUTO");
$subject = mb_encode_mimeheader($subject);

$result = mail($to, $subject, $body, $headers, $sendmail_params);


jc AT mega-bucks DOT co DOT jp
21 years ago
I was trying to send japanese email and had a hell of a time getting it to work. I finally stumbled across mb_send_mail() and it did everything I wanted *except* that it only send plain text emails ... sending HTML contents was impossible.

I finally whipped this up. I'm posting in case someone finds it useful.

function send_japanese_mail($to, $subject, $body, $from, $from_email, $is_html_content=false) {

$headers = "MIME-Version: 1.0\\n" ;
$headers .= "From: $from <$from_email>\\n";
$headers .= "Reply-To: $from <$from_email>\\n";

/* If the body is HTML or plain text set the Content-Type header accordingly */

if ($is_html_content) {
$headers .= "Content-Type: text/html;charset=ISO-2022-JP\\n";
/* turn all line breaks into BR tags */
$body = nl2br($body);
else {
$headers .= "Content-Type: text/plain;charset=ISO-2022-JP\\n";

/* need to convert body to same encoding as stated in Content-Type header above */

$body = mb_convert_encoding($body, "ISO-2022-JP","AUTO");

/* set any sendmail params, optional ... */
$sendmail_params = "-f$from_email";

The subject is actually a "header" and can/will get mangled
if it contains non-ASCII characters. So we need to convert
the subject to something containing only ASCII characters.

First we convert the subject to the same encoding as the
body, then we use mb_encode_mimeheader() to make the subject
line all ASCII characters.

$subject = mb_convert_encoding($subject, "ISO-2022-JP","AUTO");
$subject = mb_encode_mimeheader($subject);

mail($to, $subject, $body, $headers, $sendmail_params);
no dot email dot address at example dot com
21 years ago
Tested with PHP 4.2.2 on Linux: Please note that if you're using Unicode (mb_language("uni")) and you attempt to send mail with mb_send_mail(), you will need to base64_encode() the message body - mb_send_mail() doesn't do that for you. It does, however, issue the correct message headers, so you don't need to worry about that.

Also note that neither mb_language() nor mb_send_mail() is able to convert your message to UTF-8. *You* need to provide the UTF-8-encoded (and base64-encoded) message, and then mb_send_mail() will issue the correct message headers.

Here's an example of sending an UTF-8-encoded message with mb_send_mail():

$body = chunk_split(base64_encode("International characters"));
mb_send_mail("", "Subject", $body);

If the receiving mail client supports UTF-8 properly, you will be able to send messages that contain a mix of all kinds of characters (e.g., you could send Thai, Chinese, and Danish characters in the same message). Not all mail clients support UTF-8, though. At the time of writing, some of the more popular Windows email clients - Eudora and Pegasus Mail - don't. There are a number of email clients with working support for UTF-8. These include Outlook Express, KMail, Mozilla, Netscape 6/7, Sylpheed, Evolution and others.
14 years ago
If you have problem using mb_send_mail to send utf-8 mails, you have to know the following things (I've spent hours on the net before finding the correct php code) :

- You have to use the mb_encode_mimeheader function on the sender name and on the recipient name (on names, not on emails !).
- Subject and message are automatically encoded.
- Add - at least - the following header :

$headers = "Mime-Version: 1.0\n";
$headers .= "Content-Type: text/plain;charset=UTF-8\n";
$headers .= "From: $sender";

- Last but not least, beware of the internal encoding, which is needed by mb_encode_mimeheader function in order to encode properly. I had to set the internal encoding to UTF-8 in order to make it work properly :

contact-form at contactrobot dot com
11 years ago
While using the right tags mentioned in other comments (mb_internal_encoding, Content-Type, etc) ...

mb_send_mail would properly encode special characters in plain text emails, for both subject and message

mb_send_mail would not properly encode special characters in subject for multi-part messages (text+html)
dynamis at skillup dot jp
20 years ago
As others say, mb_encode_mimeheader() seems to have a bug with JIS(ISO-2022-JP) encording. Token indicating start and end of multibyte char is inserted only before start of encoding and after the all.
We need the tokens at start and end of *all* encoded-text.
# PHP 4.3.2

So, we needs some workaround.

The post by "gordon at kanazawa-gu dot ac dot jp" seems to work well, but it doesn't. JIS nees some special tokens and base64_encode does'nt output them, so the code cannot used.

The post "RE: N03L in Japan", which simply splitting words in eash 10 chars is good enough in most case, there are some problem left. When there are some splited parts starting with ascii chars, 1 additional space will be inserted.
# RFC2047 only say within 76 words, shorter is not bad.

Additionally, thought it is really rare case, when we use "=?charset?" as literal string, we have to escape them.
# Some mailer can actually send this without escape and header will be broken. :(

Now, a little non-smart but maybe more accurate code is below function. I tested only with ISO-2022-JP, only in costomized phpBB2.0.5, only some cases.
As far as my test this code worked well, but I'm not sure.

# $str: source text
# $indent: ex. for "Subject: " header, give 9 and first line will be shorter than 76-1-9=66
# $encoding: source text encoding
# $mail_encoding: $str will be converted into this before base64 encode

function encode_mimeheader($str, $indent = 0, $encoding = 'utf-8', $mail_encoding = 'iso-2022-jp')
$start_delimiter = strtoupper("=?$mail_encoding?B?");
$start_pattern = strtoupper("=\\?$mail_encoding\\?B\\?");
$end_delimiter = '?=';

$str = mb_convert_encoding($str, $mail_encoding, $encoding);
$length = mb_strlen($str, $mail_encoding);
$max_part_length = 20; // enough short in most case (you can change this default value)

for ($i=0, $index=0; $index<$length; $i++) {
$part_length = $max_part_length;
$s = mb_substr($str, $index, $part_length, $mail_encoding);
// workaround for literally used start delimiter (without below, subject may break)
// note: mb_encode_mimeheader() don't encode ascii including start delimiter
if (preg_match('/^' . $start_pattern . '/i', $s))
$lines[$i] = $start_delimiter . base64_encode($start_delimiter) . "?=";
$index += strlen($start_delimiter);

$lines[$i] = mb_encode_mimeheader($s, $mail_encoding);
while (strlen($lines[$i]) > 76-1 - ($i?0:$indent)) { // max par line - first space - indent (first line only)
$part_length = floor($part_length * (76-1 - ($i?0:$indent)) / strlen($lines[$i])); // at least 1 decrement
$s = mb_substr($str, $index, $part_length, $mail_encoding);
$lines[$i] = mb_encode_mimeheader($s, $mail_encoding);

// workaround for starting new line with ascii (without below, 1 space may cut in)
// note: mb_encode_mimeheader() starts encode after encounterring multibyte char
if ($i > 0 && !preg_match('/^' . $start_pattern . '/i', $lines[$i]))
$p = strpos($lines[$i], $start_delimiter); //never 0 (false when not found)
$p = $p ? $p : strlen($lines[$i]);
$lines[$i] = $start_delimiter . base64_encode(substr($lines[$i], 0, $p)) . "?=";
$part_length = $p;
$index += $part_length;
$str = join("\r\n ", $lines); // RFC 2047,822 say newline must be ^\r\n, not only\n
return $str;
phpguru at hotmail dot com
21 years ago
There is another way of encoding Japanese language to send email without worrying about mb_functions:

Download PHP Jcode from
and use JcodeConvert function with base64_encode function for the e-mail header and the subject.

$email_to = "";

$_POST["name"] = strip_tags(trim($_POST["name"]));
$name = "=?ISO-2022-JP?B?". base64_encode(JcodeConvert($_POST["name"], 2, 3)). "?=";
$_POST["email"] = strip_tags(trim($_POST["email"]));
$_POST["subject"] = strip_tags(trim($_POST["subject"]));
$email_subject = "=?ISO-2022-JP?B?". base64_encode(JcodeConvert($_POST["subject"], 2, 3)). "?=";
$_POST["body"] = strip_tags(trim($_POST["body"]));

$email_header = "From: $name <". $_POST["email"] .">\n";
$email_header .= "Reply-To: ". $_POST["email"] ."\n";
$email_header .= "Content-transfer-encoding: 7bit\n";
$email_header .= "Content-type: text/plain; charset=\"iso-2022-jp\"\n\n";

$email_body = "blah blah blah.\n"

mail($email_to, $email_subject, $email_body, $email_header);
N03L in Japan
21 years ago
First of all, don't use nl2br in newer php versions unless you WANT to write'll get <br /> tags.

Secondly, you should use JIS, not ISO-2022-JP as the convert TO encoding. If you use ISO... mb_encode_mimeheader seems to fail. They're the same charset anyway.

Now here's why I am really writing. I just discovered that mb_send_mail and mb_encode_mimeheader cannot support hankaku (single byte kana in (S)JIS) at all. If you are making apps for the keitai (mobile) market, this won't do. Therefore, undo your overloading on the mail function and use regular mail and convert everything yourself like this. This is what we did. It seems to work for us. Your mileage may vary.

$strMBS = mb_convert_encoding($strMailBodySend, "JIS", "EUC-JP");

$strMS = mb_encode_mimeheader( mb_convert_encoding($strMailSubj, "JIS", "EUC-JP") );

mail($strToMail, $strMS, $strMBS, $strFrom);
17 years ago
Be careful, mb_send_mail chokes if you try and send a multipart e-mail.
Ran Hamada ( rhamada at sdcj dot co dot jp )
21 years ago
You may not use mb_encode_mimeheader() with mb_convert_encoding() to make subject as follows. It causes mojibake in several strings.
mb_encode_mimeheader( mb_convert_encoding($strMailSubj, "JIS", "EUC-JP") )

Set mb_internal_encoding() to *subject's* encoding and call mb_encode_mimeheader.


$__lang = mb_language();
$__enc = mb_internal_encoding();
mb_internal_encoding( mb_detect_encoding($subject) );
#mb_internal_encoding( "EUC-JP" ); #just do when you know encoding of $subject
mb_internal_encoding( $__enc );
9 years ago
I had to use mb_internal_encoding() also to get properly encoded message.
17 years ago
Yes, as far as I understood the function encodes the entrire message body with base64 and that's why it can be used to send messages with attachments.
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