PHP使用IMAP协议接收邮箱邮件的详细流程

$hostname = '{imap.gmail.com:993/imap/ssl}INBOX';
$username = 'your_email@gmail.com';
$passWord = 'your_password';

$mailbox = imap_open($hostname, $username, $password) 
  or die('Cannot connect to Gmail: ' . imap_last_error());

$folder = 'INBOX';
imap_reopen($mailbox, $hostname . $folder) or die('Cannot open folder: ' . $folder);

$unseen_emails = imap_search($mailbox, 'UNSEEN');

$emails = imap_search($mailbox, 'ALL');

foreach ($emails as $email) {
  $structure = imap_fetchstructure($mailbox, $email);

  $from = $this->parseAddress($this->findHeader($structure, 'from'));
  $to = $this->parseAddress($this->findHeader($structure, 'to'));
  $subject = $this->findHeader($structure, 'subject');
  $body = '';

  if ($structure->encoding === 0) {
    // 解析纯文本邮件
    $body = imap_fetchbody($mailbox, $email, 1);
  } else {
    // 解析HTML邮件
    $parts = $this->getParts($structure);

    foreach ($parts as $part) {
      if ($part['subtype'] === 'PLAIN') {
        $body = imap_fetchbody($mailbox, $email, $part['partnum']);
      } else if ($part['subtype'] === 'HTML') {
        $body = imap_fetchbody($mailbox, $email, $part['partnum'], FT_UID | FT_PEEK);
      }
    }
  }

  // 处理邮件内容，例如保存到数据库、发送回执等等
}

function findHeader($structure, $header_name) {
  foreach ($structure->parts as $part) {
    if (isset($part->parameters) && $part->parameters[0]->attribute == $header_name) {
      return $part->parameters[0]->value;
    }
  }

  return '';
}

function getParts($structure) {
  $parts = [];

  if ($structure->parts) {
    foreach ($structure->parts as $index => $substructure) {
      $parts[$index] = [
        'ctype' => $substructure->ctype,
        'encoding' => $substructure->encoding,
        'subtype' => $substructure->subtype,
        'partnum' => ($index + 1)
      ];

      if (isset($substructure->params['name'])) {
        $parts[$index]['filename'] = $substructure->params['name'];
      }
    }
  } else {
    $parts[0] = [
      'ctype' => $structure->ctype,
      'encoding' => $structure->encoding,
      'subtype' => $structure->subtype,
      'partnum' => 1
    ];

    if (isset($structure->params['name'])) {
      $parts[0]['filename'] = $structure->params['name'];
    }
  }

  return $parts;
}

function parseAddress($address) {
  $name = '';
  $email = '';

  foreach (imap_rfc822_parse_adrlist($address, '') as $addr) {
    if (isset($addr->mailbox) && isset($addr->host)) {
      $name = $addr->personal;
      $email = $addr->mailbox . '@' . $addr->host;
    }
  }

  return [
    'name' => $name,
    'email' => $email
  ];
}

imap_close($mailbox);