我对设置 web 服务还很陌生，我只有网络的基本知识，我正在尝试在本地服务器上设置一个 web 服务，以通过托管在我的 ISP 中的邮件服务器接收和发送邮件。
设置： - OSX - Roundcubemail - 服务器应用程序 - 带无 IP 链接的动态 IP
这是我的 default.inc.php：
// ----------------------------------
// SMTP
// ----------------------------------
// SMTP server host (for sending mails).
// To use SSL/TLS connection, enter hostname with prefix ssl:// or tls://
// If left blank, the PHP mail() function is used
// Supported replacement variables:
// %h - user's IMAP hostname
// %n - hostname ($_SERVER['SERVER_NAME'])
// %t - hostname without the first part
// %d - domain (http hostname $_SERVER['HTTP_HOST'] without the first part)
// %z - IMAP domain (IMAP hostname without the first part)
// For example %n = mail.domain.tld, %t = domain.tld
$config['smtp_server'] = ‘%n’;
// $config['smtp_server'] = ‘’;
// SMTP port (default is 25; use 587 for STARTTLS or 465 for the
// deprecated SSL over SMTP (aka SMTPS))
$config['smtp_port'] = 25;
// SMTP username (if required) if you use %u as the username Roundcube
// will use the current username for login
$config['smtp_user'] = '%u';
// $config['smtp_user'] = '';
// SMTP password (if required) if you use %p as the password Roundcube
// will use the current user's password for login
$config['smtp_pass'] = '%p';
// $config['smtp_pass'] = '';
// SMTP AUTH type (DIGEST-MD5, CRAM-MD5, LOGIN, PLAIN or empty to use
// best server supported one)
$config['smtp_auth_type'] = ‘LOGIN’;
// $config['smtp_auth_type'] = ‘’;
// Optional SMTP authentication identifier to be used as authorization proxy
$config['smtp_auth_cid'] = null;
// Optional SMTP authentication password to be used for smtp_auth_cid
$config['smtp_auth_pw'] = null;
// SMTP HELO host
// Hostname to give to the remote server for SMTP 'HELO' or 'EHLO' messages
// Leave this blank and you will get the server variable 'server_name' or
// localhost if that isn't defined.
$config['smtp_helo_host'] = '';
// SMTP connection timeout, in seconds. Default: 0 (use default_socket_timeout)
// Note: There's a known issue where using ssl connection with
// timeout > 0 causes connection errors ([url]https://bugs.php.net/bug.php?id=54511[/url])
$config['smtp_timeout'] = 0;
// SMTP socket context options
// See [url]http://php.net/manual/en/context.ssl.php[/url]
// The example below enables server certificate validation, and
// requires 'smtp_timeout' to be non zero.
// $config['smtp_conn_options'] = array(
// 'ssl' => array(
// 'verify_peer' => true,
// 'verify_depth' => 3,
// 'cafile' => '/etc/openssl/certs/ca.crt',
// ),
// );
$config['smtp_conn_options'] = null;
我得到一个：
SMTP Error (250): Authentication failed.
没有可能向任何人发送邮件。
如果我将它们更改为默认值：
$config['smtp_server'] = ‘’;
$config['smtp_port'] = 25;
$config['smtp_user'] = '';
$config['smtp_pass'] = '';
$config['smtp_auth_type'] = ‘’;
我会有不同的输出，在这里我可以在我的 ISP 的几个域之间发送和接收邮件，但我无法将邮件发送到 gmail.com 等域，收到以下错误：
SMTP Error (550): Failed to add recipient "XXX" (Please turn on SMTP Authentication in your mail client.
XXX (XXX.local) [XXX]:XXX
is not permitted to relay through this server without authentication.).
我也激活了 smtp 日志，但看不到问题出在哪里：
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 220-cpanel.X.pt ESMTP Exim 4.87 #1 Mon, 17 Oct 2016 11:16:24 +0100
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 220-We do not authorize the use of this system to transport unsolicited,
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 220 and/or bulk e-mail.
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Send: EHLO X.local
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-cpanel.X.pt Hello X.pt [X]
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-SIZE 52428800
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-8BITMIME
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-PIPELINING
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-AUTH PLAIN LOGIN
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250-STARTTLS
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250 HELP
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Send: RSET
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 250 Reset OK
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Send: QUIT
[17-Oct-2016 11:16:24 +0100]: <sbg56vpg> Recv: 221 cpanel.X.pt closing connection
我发现 SMTP 可以通过 SPF 和 DKIM 进行身份验证，但不知道这是否会干扰 SMTP 身份验证。