如何让PHPMailer autoresponder按收件邮箱返回不同HTML内容

问题场景 #

需要实现自动回复功能：

• 当外部用户发送邮件至no-reply@example.com时，自动回复指定HTML文本1
• 当发送至info@example.com时，自动回复指定HTML文本2

尝试通过判断$mail->toAddress或$mail->recipient字段设置不同回复内容，但均未生效，以下是完整代码及尝试片段：

完整代码 #

<?php
if (!isset($_GET['api_key']) || $_GET['api_key'] !== 'VALUE-OF-API') {
    echo "Access denied!";
    exit;
}

$unwantedEmails = array(
    'no-reply',
    'noreply',
    'no-return',
    'noreturn',
    'automessage',
    'auto-message',
    'notification',
    'support',
    'postmaster',
    'do-not-reply',
    'donotreply',
    'auto-reply',
    'automated-reply',
    'auto-response',
    'out-of-office',
    'vacation-reply',
    'autoresponder',
    'auto-responder',
    'auto-reply',
    'auto-reply-system',
    'auto-message',
    'auto-notification',
    'automated-message',
    'automated-response',
    'automated-email',
    'no-reply-needed',
    'noreply-necessary',
    'no-reply-requested',
    'auto-no-reply',
    'do-not-reply-automated',
    'automated-no-reply',
    'auto-response-only',
    'automated-reply-only',
    'no-reply-auto',
    'auto-message-no-reply',
    'noreply-automatic',
    'no-reply-message',
    'automated-donotreply',
    'auto-no-return',
    'automated-no-return',
    'no-reply-auto-message',
    'noreply-auto-response',
    'auto-response-noreply'
);

require 'vendor/autoload.php';
use PhpImap\Mailbox;
use PHPMailer\PHPMailer\PHPMailer;

// IMAP服务器连接信息
$hostname = '{imap.mail.me.com:993/imap/ssl/novalidate-cert}';
$username = 'example@icloud.com';
$password = 'xxx';

$mailbox = new Mailbox($hostname, $username, $password);

$answeredEmailsFile = 'answered_mails.txt';

$mailsIds = $mailbox->searchMailbox('ALL', SORTDATE, true);

$answeredEmails = [];
if (file_exists($answeredEmailsFile)) {
    $answeredEmails = unserialize(file_get_contents($answeredEmailsFile));
}

if (!empty($mailsIds)) {
    foreach ($mailsIds as $mailId) {
        if (!is_array($answeredEmails) || !in_array($mailId, $answeredEmails)) {
            $mail = $mailbox->getMail($mailId, false); 

            $from = $mail->fromAddress;

            $isUnwantedEmail = false;
            foreach ($unwantedEmails as $unwantedEmail) {
                if (stripos($from, $unwantedEmail) !== false) {
                    $isUnwantedEmail = true;
                    break;
                }
            }

            if (!$isUnwantedEmail) {
                $subject = $mail->subject;
                $date = $mail->date;
                $email_body = $mail->textPlain;

                echo "From: $from<br>";
                echo "Subject: $subject<br>";
                echo "Date: $date<br>";
                echo "<br>";

                sendAutoresponder($from, $subject, $email_body);

                $answeredEmails[] = $mailId;
            } else {
                echo "No E-Mail sent to $from because rule do not reply to '$from'<br>";
            }
        }
    }

    $fileHandle = fopen($answeredEmailsFile, 'w');
    if ($fileHandle) {
        fwrite($fileHandle, serialize($answeredEmails));
        fclose($fileHandle);
    } else {
        echo "Error: Failed to open the file for writing.";
    }
} else {
    echo "No new mails found.";
}

function sendAutoresponder($recipient, $subject, $body) {
    $mail = new PHPMailer();
    $mail->isSMTP();
    $mail->Host = 'smtp.mail.me.com';
    $mail->Port = 587;
    $mail->SMTPSecure = 'tls';
    $mail->SMTPAuth = true;
    $mail->Username = 'example@icloud.com'; 
    $mail->Password = 'xxx';

    $mail->setFrom('no-reply@example.com', 'noreply@example.com');
    $mail->addReplyTo('noreply@example.com', 'noreply@example.com');
    $mail->addAddress($recipient);
    $mail->Subject = '### Auto Message ###';
    $mail->CharSet = 'UTF-8';
    $mail->isHTML(true);
    $mail->Body = '<html><body>Text for no-reply@example.com here!</body></html>';
    
    // 疑问：如何根据收件邮箱设置自定义回复内容？

    $mail->addCustomHeader('Precedence', 'bulk');
    $mail->addCustomHeader('Auto-Submitted', 'auto-generated');

    if (!$mail->send()) {
        echo 'E-Mail konnte nicht gesendet werden.';
        echo 'Mailer Error: ' . $mail->ErrorInfo;
    } else {
        echo 'Autoresponded to ' . $recipient . ' sent.';
    }
}
?>

尝试的无效代码片段 #

// 判断邮件是否发送到no-reply地址
if (stripos($mail->toAddress, 'no-reply@example.com') !== false) {
    $email_body = "<html><body>E-Mail empfangen an no-reply@example.com</body></html>";
} else {
    $email_body = "<html><body>E-Mail empfangen an info@example.com</body></html>";
}

// 判断邮件是否发送到no-reply地址
if (stripos($mail->recipient, 'no-reply@example.com') !== false) {
    $email_body = "<html><body>E-Mail empfangen an no-reply@example.com</body></html>";
} else {
    $email_body = "<html><body>E-Mail empfangen an example.com</body></html>";
}

问题原因 #

使用的PhpImap库中，Mail对象的收件人信息并非存放在toAddress或recipient字段，而是存储在$mail->to数组中（数组元素为包含邮箱地址的对象），因为单封邮件可能包含多个收件人，所以需要遍历该数组匹配目标邮箱。

解决方案 #

步骤1：在主逻辑中匹配目标收件邮箱并选择回复内容 #

在获取邮件后，遍历$mail->to数组判断收件邮箱，生成对应的回复HTML内容，再将该内容传递给sendAutoresponder函数：

// ... 原有代码 ...
if (!$isUnwantedEmail) {
    $subject = $mail->subject;
    $date = $mail->date;
    $email_body = $mail->textPlain;

    echo "From: $from<br>";
    echo "Subject: $subject<br>";
    echo "Date: $date<br>";
    echo "<br>";

    // 新增：判断邮件收件邮箱，选择对应回复内容
    $replyHtml = '';
    foreach ($mail->to as $toRecipient) {
        $toEmail = $toRecipient->mail;
        if ($toEmail === 'no-reply@example.com') {
            $replyHtml = '<html><body>Text for no-reply@example.com here!</body></html>';
            break;
        } elseif ($toEmail === 'info@example.com') {
            $replyHtml = '<html><body>Text for info@example.com here!</body></html>';
            break;
        }
    }
    // 兜底：如果匹配不到指定邮箱，设置默认回复内容
    if (empty($replyHtml)) {
        $replyHtml = '<html><body>Default auto-reply text here!</body></html>';
    }

    // 修改：传递回复HTML内容给函数
    sendAutoresponder($from, $subject, $email_body, $replyHtml);

    $answeredEmails[] = $mailId;
}
// ... 原有代码 ...

步骤2：修改sendAutoresponder函数接收回复内容参数 #

更新函数定义，新增$replyHtml参数，并将其赋值给$mail->Body：

function sendAutoresponder($recipient, $subject, $body, $replyHtml) {
    $mail = new PHPMailer();
    $mail->isSMTP();
    $mail->Host = 'smtp.mail.me.com';
    $mail->Port = 587;
    $mail->SMTPSecure = 'tls';
    $mail->SMTPAuth = true;
    $mail->Username = 'example@icloud.com'; 
    $mail->Password = 'xxx';

    $mail->setFrom('no-reply@example.com', 'noreply@example.com');
    $mail->addReplyTo('noreply@example.com', 'noreply@example.com');
    $mail->addAddress($recipient);
    $mail->Subject = '### Auto Message ###';
    $mail->CharSet = 'UTF-8';
    $mail->isHTML(true);
    // 修改：使用传入的回复HTML内容
    $mail->Body = $replyHtml;

    $mail->addCustomHeader('Precedence', 'bulk');
    $mail->addCustomHeader('Auto-Submitted', 'auto-generated');

    if (!$mail->send()) {
        echo 'E-Mail konnte nicht gesendet werden.';
        echo 'Mailer Error: ' . $mail->ErrorInfo;
    } else {
        echo 'Autoresponded to ' . $recipient . ' sent.';
    }
}

说明 #

• $mail->to数组中的每个元素是一个对象，其mail属性存储收件人邮箱地址
• 遍历数组匹配到目标邮箱后立即跳出循环，避免重复匹配
• 增加兜底逻辑，确保即使没有匹配到指定邮箱也能发送默认回复

内容的提问来源于stack exchange，提问作者user21420849