PHP IMAP邮件处理实战：构建企业级邮件附件自动处理系统

graph TD
    A[启动任务] --> B[连接邮箱服务器]
    B --> C[获取邮件列表]
    C --> D[筛选符合条件的邮件]
    D --> E[提取邮件附件]
    E --> F[处理附件内容]
    F --> G[上传到协作平台]
    G --> H[创建记录]
    H --> I[清理临时文件]

/**
 * 连接邮箱服务器
 * @param $account
 * @return resource
 */
private function connectToMailbox($account)
{
    $hostname = "{" . $account['host'] . ":" . $account['port'] . "/" . $account['protocol'] . "}INBOX";
    $username = $account['email'];
    $password = $account['password'];

    $mailbox = imap_open($hostname, $username, $password);
    if (!$mailbox) {
        throw new \Exception("无法连接到邮箱服务器: " . imap_last_error());
    }

    return $mailbox;
}

/**
 * 获取邮件列表
 * @param $mailbox
 * @param $account
 * @return array
 */
private function getEmailList($mailbox, $account)
{
    $emails = [];

    // 按日期降序排序获取邮件
    $emailIds = imap_sort($mailbox, SORTDATE, 1);
    
    // 只取前100条
    $latestEmailIds = array_slice($emailIds, 0, 100);
    
    foreach ($latestEmailIds as $emailId) {
        $emailInfo = $this->getEmailInfo($mailbox, $emailId, $account['email']);
        if ($emailInfo) {
            // 筛选条件：有附件且主题以'Scan Data from'开头
            if ($emailInfo['has_attachments'] && strpos($emailInfo['subject'], 'Scan Data from') === 0) {
                $emails[] = $emailInfo;
            }
        }
    }

    return $emails;
}

/**
 * 获取邮件信息
 * @param $mailbox
 * @param $emailId
 * @param $email
 * @return array|null
 */
private function getEmailInfo($mailbox, $emailId, $email)
{
    $header = imap_headerinfo($mailbox, $emailId);
    $structure = imap_fetchstructure($mailbox, $emailId);

    if (!$header || !$structure) {
        return null;
    }

    $uid = imap_uid($mailbox, $emailId);
    // 通过email+uid生成md5值作为全局唯一标识符
    $mail_id = md5($email . $uid);

    // 格式化日期为 Y-m-d H:i:s 格式
    $formattedDate = date('Y-m-d H:i:s', strtotime($header->date));
    
    $emailInfo = [
        'id' => $emailId,
        'uid' => $uid,
        'mail_id' => $mail_id,
        'subject' => $header->subject,
        'from' => $header->from[0]->mailbox . '@' . $header->from[0]->host,
        'date' => $header->date,
        'formatted_date' => $formattedDate,
        'has_attachments' => $this->hasAttachments($structure)
    ];

    return $emailInfo;
}

/**
 * 检查邮件是否有附件
 * @param $structure
 * @return bool
 */
private function hasAttachments($structure)
{
    if (isset($structure->parts) && count($structure->parts)) {
        foreach ($structure->parts as $part) {
            if ($part->ifdisposition && strtolower($part->disposition) == 'attachment') {
                return true;
            }
        }
    }
    return false;
}

/**
 * 提取附件
 * @param $mailbox
 * @param $emailId
 * @param $structure
 * @return array
 */
private function extractAttachments($mailbox, $emailId, $structure, $partNumber = '')
{
    $attachments = [];

    if (isset($structure->parts) && count($structure->parts)) {
        foreach ($structure->parts as $key => $part) {
            $currentPartNumber = $partNumber ? $partNumber . '.' . ($key + 1) : ($key + 1);

            if ($part->ifdisposition && strtolower($part->disposition) == 'attachment') {
                $attachment = [
                    'filename' => $this->getAttachmentFilename($part),
                    'content' => imap_fetchbody($mailbox, $emailId, $currentPartNumber),
                    'encoding' => $part->encoding
                ];
                $attachments[] = $attachment;
            } elseif (isset($part->parts) && count($part->parts)) {
                $attachments = array_merge($attachments, $this->extractAttachments($mailbox, $emailId, $part, $currentPartNumber));
            }
        }
    }

    return $attachments;
}

/**
 * 解码附件内容
 * @param $content
 * @param $encoding
 * @return string
 */
private function decodeAttachment($content, $encoding)
{
    switch ($encoding) {
        case 3: // BASE64
            return base64_decode($content);
        case 4: // QUOTED-PRINTABLE
            return quoted_printable_decode($content);
        default:
            return $content;
    }
}

/**
 * 保存附件到本地
 * @param $content
 * @param $filename
 * @return string
 */
private function saveAttachment($content, $filename)
{
    $filePath = $this->savePath . DS . $filename;
    file_put_contents($filePath, $content);
    return $filePath;
}

// 通过email+uid生成md5值作为全局唯一标识符
$mail_id = md5($email . $uid);

// 通过mail_id查询飞书多维表格是否已存在记录
if ($this->checkMailIdExistsInFeiShu($email['mail_id'])) {
    // 如果记录已存在，则跳过处理
    $this->logError("邮件 {$email['mail_id']} 已在飞书表格中存在，跳过处理");
    return;
}

/**
 * 关闭邮箱连接
 * @param $mailbox
 * @return void
 */
private function closeMailbox($mailbox)
{
    if ($mailbox) {
        imap_close($mailbox);
    }
}

private function processEmailAccount($account)
{
    try {
        // 连接邮箱服务器
        $mailbox = $this->connectToMailbox($account);
        
        // 处理邮件...
        
        // 关闭邮箱连接
        $this->closeMailbox($mailbox);
        $this->setCurrentMailbox(null);
    } catch (\Exception $e) {
        // 记录错误日志
        $this->logError("处理邮箱账号 {$account['email']} 时出错: " . $e->getMessage());
    }
}

// 删除临时文件
if (file_exists($filePath)) {
    unlink($filePath);
}

$emailAccounts = [
    [
        'name' => '用户姓名',
        'email' => 'user@example.com',
        'password' => '邮箱密码',
        'host' => 'imap.mailserver.com',
        'port' => '993',
        'protocol' => 'ssl',
    ],
    // 更多邮箱账号...
];