是的，这是可能的。WordPress定义了一个名为wp_new_user_notification. 您可以通过创建自己的版本（也称为wp_new_user_notification) 在您自己的主题或插件中。

您可能希望从复制contents of the existing core version 输入您自己的副本。现在，您可以根据自己的需要自定义逻辑。

由于此函数通过$user_id 作为第一个参数，您可以使用get_userdata 获取有关用户的更多信息（例如，该用户的角色），然后根据其角色发送不同的内容。

$user_data = get_userdata( $user_id );
if ( ! empty( $user_data->roles ) ) {
    if ( in_array( \'role_a\', $user_data->roles, true ) {
        // custom content for role a
    } elseif ( in_array( \'role_b\', $user_data->roles, true ) {
        // custom content for role b
    }
}

我已经解决了这个问题。谢谢你的大力帮助@jared cobb

            function send_welcome_email_to_new_user($user_id) {
            $user = get_userdata($user_id);
            $user_email = $user->user_email;

            // email will send only for "A" registers
            if ( in_array( \'A\', $user->roles )) {
              $to = $user_email;
              $subject = "Hi A, welcome to our site!";
              $body = \'
                        <h1>Dear A,</h1></br>
                        <p>Thank you for joining our site. Your account is now active.</p>
              \';
              $headers = array(\'Content-Type: text/html; charset=UTF-8\');
              if (wp_mail($to, $subject, $body, $headers)) {
                error_log("email has been successfully sent to user whose email is " . $user_email);
              }
            }

            // email will send only for "B" registers
            if ( in_array( \'B\', $user->roles )) {
              $to = $user_email;
              $subject = "Hi B, welcome to our site!";
              $body = \'
                        <h1>Dear B,</h1></br>
                        <p>Thank you for joining our site. Your account is now active.</p>
              \';
              $headers = array(\'Content-Type: text/html; charset=UTF-8\');
              if (wp_mail($to, $subject, $body, $headers)) {
                error_log("email has been successfully sent to user whose email is " . $user_email);
              }
            }

            }
            add_action(\'user_register\', \'send_welcome_email_to_new_user\');