PHP根据HTML表单部门选择发送邮件逻辑问题求助

我有一个带部门选择的回电请求HTML表单，希望通过PHP根据用户选择的部门将请求发送到对应邮箱，但当前无论选哪个部门，邮件都会发送至sales@domain.co.uk，怀疑PHP的if语句存在问题。以下是我的代码：

HTML表单代码 #

<form action="js/call.php" method="post"  class="contactForm">
                    
<div class="row">
<div class="form-group col-6">
<input type="text" class="form-control" id="name" name="name" required maxlength="50" placeholder="Name" >
</div>

<div class="form-group col-6">
<input type="text" class="form-control" id="phone" name="phone" required maxlength="50" placeholder="Contact Number">
</div>
</div>

<div class="form-group col-12">
<select id="department-chosen"  class="form-control" name="department-chosen" required>
<option hidden value="">Please select a department</option>
   <option value="sales">Bike Sales</option>
  <option value="service">Workshop</option>
  <option value="parts">Parts</option>
  <option value="clothing">Clothing / Accessories</option>
</select></div>

<div><input type="text" name="reference" id="reference"   tabindex="-1" autocomplete="off" > </div>

<!-- START CAPTCHA -->
<br>

<div class="float-end"><button type="submit" class="btn btn-af1" name="text" value="Send">
          <i class="pe-1 fa fa-paper-plane"></i>Send</button>
</div> 
 </form>    

PHP代码 #

<?php 
// if the reference field is not empty
if(!empty($_POST['reference'])) die();
// if the test field is empty
if(isset($_POST['reference']) && $_POST['test'] == ''){

if($_POST['department-chosen']  == 'sales') $to = "sales@domain.co.uk";
elseif($_POST['department-chosen']  == 'service') $to = "service@domain.co.uk";
elseif($_POST['department-chosen']  == 'parts') $to = "parts@domain.co.uk";
else $to = "clothing@domain.co.uk";

             
 $from = $_REQUEST['phone'] ; 
 $name = $_REQUEST['name'] ;
 $subject = "Call back requested from website"; 
 
 $fields = array(); 
 $fields["name"] = "Name";
 $fields["phone"] = "Phone"; 
 $fields["department-chosen"] = "Department"; 
 $fields["reference"] = "reference";
 

 $body = "We have received the following 'call back' request:

"; foreach($fields as $a => $b){   $body .= sprintf("%20s: %s
",$b,$_REQUEST[$a]); } 
 

 
 $send = mail($to, $subject, $body); 
 if($send) 
 {header( "Location: https://www.domain.co.uk/thankyou.htm" );} 
 




 else 
 {print "We encountered an error sending your mail, please notify service@domain.co.uk"; } 
 }
 ?> 

问题分析与修复方案 #

核心问题 #

1. 无效的条件判断：PHP代码中$_POST['test']对应的字段在表单中不存在（表单里只有名为text的提交按钮），这会导致条件isset($_POST['reference']) && $_POST['test'] == ''在部分PHP环境中无法正常触发，或因未定义变量产生警告，进而导致后续部门判断代码未执行。若之前代码中$to默认值为sales@domain.co.uk，就会出现所有邮件都发往该地址的情况。
2. $from字段不合法：邮件的From地址设置为用户输入的电话号码，不符合SMTP规范，可能导致邮件被拒收或进入垃圾邮箱。

修复后的PHP代码 #

<?php
// 反垃圾邮件：如果机器人填充了隐藏的reference字段，直接终止脚本
if (!empty($_POST['reference'])) {
    die();
}

// 确保表单已提交且department-chosen字段存在
if (isset($_POST['department-chosen'])) {
    // 用数组映射部门和邮箱，更清晰易维护
    $departmentEmails = [
        'sales' => 'sales@domain.co.uk',
        'service' => 'service@domain.co.uk',
        'parts' => 'parts@domain.co.uk',
        'clothing' => 'clothing@domain.co.uk'
    ];

    // 获取目标邮箱，若部门值不在映射中，默认使用sales邮箱（可按需调整）
    $to = isset($departmentEmails[$_POST['department-chosen']]) 
        ? $departmentEmails[$_POST['department-chosen']] 
        : 'sales@domain.co.uk';

    $name = $_POST['name'];
    $phone = $_POST['phone'];
    $department = $_POST['department-chosen'];
    $subject = "Call back requested from website";

    // 构建邮件内容，移除无用的reference字段
    $body = "We have received the following 'call back' request:\n\n";
    $body .= sprintf("%20s: %s\n", "Name", $name);
    $body .= sprintf("%20s: %s\n", "Phone", $phone);
    $body .= sprintf("%20s: %s\n", "Department", $department);

    // 设置合法的From地址，使用网站官方邮箱
    $headers = "From: Website Call Back <no-reply@domain.co.uk>\r\n";
    $headers .= "Reply-To: $name <$phone>\r\n"; // 可选：设置回复到用户电话（部分邮箱支持）

    // 发送邮件
    $send = mail($to, $subject, $body, $headers);

    if ($send) {
        header("Location: https://www.domain.co.uk/thankyou.htm");
        exit(); // 跳转后终止脚本，避免后续代码执行
    } else {
        print "We encountered an error sending your mail, please notify service@domain.co.uk";
    }
} else {
    // 若department-chosen字段未提交，提示错误
    print "Please select a valid department.";
}
?>

修复说明 #

1. 移除无效的$_POST['test']判断：只保留针对department-chosen字段的存在性检查，确保部门判断代码能正常执行。
2. 使用数组映射部门与邮箱：相比if-else链，数组映射更简洁，后续新增部门只需修改数组即可，降低出错概率。
3. 修正From字段：使用合法的网站邮箱作为发件地址，符合SMTP规范，提升邮件送达率。
4. 优化邮件内容：移除无用的reference字段，让邮件内容更清晰。
5. 添加exit()跳转后终止脚本：避免header跳转后后续代码继续执行。

内容的提问来源于stack exchange，提问作者Jan Cooper