这对我很有用。它还附加了多个附件。很容易

<?php

if ($_POST && isset($_FILES['file'])) {
    $recipient_email = "recipient@yourmail.com"; //recepient
    $from_email = "info@your_domain.com"; //from email using site domain.
    $subject = "Attachment email from your website!"; //email subject line

    $sender_name = filter_var($_POST["s_name"], FILTER_SANITIZE_STRING); //capture sender name
    $sender_email = filter_var($_POST["s_email"], FILTER_SANITIZE_STRING); //capture sender email
    $sender_message = filter_var($_POST["s_message"], FILTER_SANITIZE_STRING); //capture message
    $attachments = $_FILES['file'];

    //php validation
    if (strlen($sender_name) < 4) {
        die('Name is too short or empty');
    }
    if (!filter_var($sender_email, FILTER_VALIDATE_EMAIL)) {
        die('Invalid email');
    }
    if (strlen($sender_message) < 4) {
        die('Too short message! Please enter something');
    }

    $file_count = count($attachments['name']); //count total files attached
    $boundary = md5("specialToken$4332"); // boundary token to be used

    if ($file_count > 0) { //if attachment exists
        //header
        $headers = "MIME-Version: 1.0\r\n";
        $headers .= "From:" . $from_email . "\r\n";
        $headers .= "Reply-To: " . $sender_email . "" . "\r\n";
        $headers .= "Content-Type: multipart/mixed; boundary = $boundary\r\n\r\n";

        //message text
        $body = "--$boundary\r\n";
        $body .= "Content-Type: text/plain; charset=ISO-8859-1\r\n";
        $body .= "Content-Transfer-Encoding: base64\r\n\r\n";
        $body .= chunk_split(base64_encode($sender_message));

        //attachments
        for ($x = 0; $x < $file_count; $x++) {
            if (!empty($attachments['name'][$x])) {

                if ($attachments['error'][$x] > 0) { //exit script and output error if we encounter any
                    $mymsg = array(
                        1 => "The uploaded file exceeds the upload_max_filesize directive in php.ini",
                        2 => "The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form",
                        3 => "The uploaded file was only partially uploaded",
                        4 => "No file was uploaded",
                        6 => "Missing a temporary folder");
                    die($mymsg[$attachments['error'][$x]]);
                }

                //get file info
                $file_name = $attachments['name'][$x];
                $file_size = $attachments['size'][$x];
                $file_type = $attachments['type'][$x];

                //read file 
                $handle = fopen($attachments['tmp_name'][$x], "r");
                $content = fread($handle, $file_size);
                fclose($handle);
                $encoded_content = chunk_split(base64_encode($content)); //split into smaller chunks (RFC 2045)

                $body .= "--$boundary\r\n";
                $body .= "Content-Type: $file_type; name=" . $file_name . "\r\n";
                $body .= "Content-Disposition: attachment; filename=" . $file_name . "\r\n";
                $body .= "Content-Transfer-Encoding: base64\r\n";
                $body .= "X-Attachment-Id: " . rand(1000, 99999) . "\r\n\r\n";
                $body .= $encoded_content;
            }
        }
    } else { //send plain email otherwise
        $headers = "From:" . $from_email . "\r\n" .
                "Reply-To: " . $sender_email . "\n" .
                "X-Mailer: PHP/" . phpversion();
        $body = $sender_message;
    }

    $sentMail = @mail($recipient_email, $subject, $body, $headers);
    if ($sentMail) { //output success or failure messages
        die('Thank you for your email');
    } else {
        die('Could not send mail! Please check your PHP mail configuration.');
    }
}
?>

由于它们指定的附件格式(application/octet-stream)，上面的答案都不适合我。使用application/pdf可获得pdf文件的最佳效果。

<?php

// just edit these 
$to          = "email1@domain.com, email2@domain.com"; // addresses to email pdf to
$from        = "sent_from@domain.com"; // address message is sent from
$subject     = "Your PDF email subject"; // email subject
$body        = "<p>The PDF is attached.</p>"; // email body
$pdfLocation = "./your-pdf.pdf"; // file location
$pdfName     = "pdf-file.pdf"; // pdf file name recipient will get
$filetype    = "application/pdf"; // type

// creates headers and mime boundary
$eol = PHP_EOL;
$semi_rand     = md5(time());
$mime_boundary = "==Multipart_Boundary_$semi_rand";
$headers       = "From: $from$eolMIME-Version: 1.0$eol" .
    "Content-Type: multipart/mixed;$eol boundary=\"$mime_boundary\"";

// add html message body
$message = "--$mime_boundary$eol" .
    "Content-Type: text/html; charset=\"iso-8859-1\"$eol" .
    "Content-Transfer-Encoding: 7bit$eol$eol$body$eol";

// fetches pdf
$file = fopen($pdfLocation, 'rb');
$data = fread($file, filesize($pdfLocation));
fclose($file);
$pdf = chunk_split(base64_encode($data));

// attaches pdf to email
$message .= "--$mime_boundary$eol" .
    "Content-Type: $filetype;$eol name=\"$pdfName\"$eol" .
    "Content-Disposition: attachment;$eol filename=\"$pdfName\"$eol" .
    "Content-Transfer-Encoding: base64$eol$eol$pdf$eol--$mime_boundary--";

// Sends the email
if(mail($to, $subject, $message, $headers)) {
    echo "The email was sent.";
}
else {
    echo "There was an error sending the mail.";
}

您可以尝试使用以下代码:

    $filename = 'myfile';
    $path = 'your path goes here';
    $file = $path . "/" . $filename;

    $mailto = 'mail@mail.com';
    $subject = 'Subject';
    $message = 'My message';

    $content = file_get_contents($file);
    $content = chunk_split(base64_encode($content));

    // a random hash will be necessary to send mixed content
    $separator = md5(time());

    // carriage return type (RFC)
    $eol = "\r\n";

    // main header (multipart mandatory)
    $headers = "From: name <test@test.com>" . $eol;
    $headers .= "MIME-Version: 1.0" . $eol;
    $headers .= "Content-Type: multipart/mixed; boundary=\"" . $separator . "\"" . $eol;
    $headers .= "Content-Transfer-Encoding: 7bit" . $eol;
    $headers .= "This is a MIME encoded message." . $eol;

    // message
    $body = "--" . $separator . $eol;
    $body .= "Content-Type: text/plain; charset=\"iso-8859-1\"" . $eol;
    $body .= "Content-Transfer-Encoding: 8bit" . $eol;
    $body .= $message . $eol;

    // attachment
    $body .= "--" . $separator . $eol;
    $body .= "Content-Type: application/octet-stream; name=\"" . $filename . "\"" . $eol;
    $body .= "Content-Transfer-Encoding: base64" . $eol;
    $body .= "Content-Disposition: attachment" . $eol;
    $body .= $content . $eol;
    $body .= "--" . $separator . "--";

    //SEND Mail
    if (mail($mailto, $subject, $body, $headers)) {
        echo "mail send ... OK"; // or use booleans here
    } else {
        echo "mail send ... ERROR!";
        print_r( error_get_last() );
    }

编辑14 - 6 - 2018

为更多的可读性在一些电子邮件提供商 使用

$body .= $eol。美元的消息。eol美元。eol美元;而且 $body .= $eol。美元的内容。eol美元。eol美元;

我同意评论中的@MihaiIorga -使用PHPMailer脚本。听起来你拒绝是因为你想要更简单的选择。相信我，比起自己使用PHP内置的mail()函数，PHPMailer是一个更简单的选择。PHP的mail()函数真的不是很好。

使用PHPMailer:

下载PHPMailer脚本:http://github.com/PHPMailer/PHPMailer 提取归档文件并将脚本文件夹复制到项目中方便的位置。 包括主脚本文件——require_once('path/to/file/class.phpmailer.php');

现在，发送带有附件的电子邮件从异常困难变得异常简单:

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

$email = new PHPMailer();
$email->SetFrom('you@example.com', 'Your Name'); //Name is optional
$email->Subject   = 'Message Subject';
$email->Body      = $bodytext;
$email->AddAddress( 'destinationaddress@example.com' );

$file_to_attach = 'PATH_OF_YOUR_FILE_HERE';

$email->AddAttachment( $file_to_attach , 'NameOfFile.pdf' );

return $email->Send();

只有一行$email-> addatattachment ();——再简单不过了。

如果使用PHP的mail()函数，则需要编写大量代码，并且可能会遇到许多很难找到的错误。

在与格式糟糕的附件斗争了一段时间后，我使用了以下代码:

$email = new PHPMailer();
$email->From      = 'from@somedomain.com';
$email->FromName  = 'FromName';
$email->Subject   = 'Subject';
$email->Body      = 'Body';
$email->AddAddress( 'to@somedomain.com' );
$email->AddAttachment( "/path/to/filename.ext" , "filename.ext", 'base64', 'application/octet-stream' );
$email->Send();

你可以使用我创建的这个类发送常规邮件或附件邮件。

下面是如何使用它的示例链接。

https://github.com/Nerdtrix/EZMAIL