电子邮件使用php mail（）在垃圾邮件文件夹中丢弃

Question

 define("WEBMASTER_EMAIL","");<br/>

$from_Email = "garglawfirm@gmail.com";<br/>

//向客户发送电子邮件......

$subject = "Trademark Registration Request";<br/>
$message = "Hi ".$client_applicantName.",<br/>

我们已收到您的商标注册申请。我们将继续进行！..
您的请求ID为：".$lastInserId." and Applicant Type is: ".$client_applicantType."

由<a href='http://www.glf.gssltd.co.in'>Garg Law Firm";

发送

$send = @mail(WEBMASTER_EMAIL, $subject, $message,
       "To: ".$client_applicantEmail."\r\n"
      ."From: ".$from_Email."\r\n"
      ."Return-path: ".$client_applicantEmail."\r\n"
      ."MIME-Version: 1.0\r\n"
      ."Content-type: text/html; charset=iso-8859-1\r\n");<br/>
if($send){<br/>
       echo "<script type='text/javascript'>";<br/>
       echo "alert('Client Details Successfully Saved. Mail Sent To Your Email-Id.');window.location.href='http://glf.gssltd.co.in/search-trademark-app'";<br/>
       echo "</script>";<br/>    
      }else{<br/>
          echo "<script type='text/javascript'>";<br/>
          echo "alert('Unable to Save Client Details.');";<br/>
          echo "</script>";<br/>
      }