Cannot use variable $_SERVER['HTTP_HOST'] in php mail()

Question

I tested this:

<?php
 $to = "recipient@example.com";
 $subject = "Hi!";
 $server = $_SERVER['HTTP_HOST'];
 $body = "From: ". $server. "<br>";
 $body .= "Hi,\n\nHow are you?";
 if (mail($to, $subject, $body)) {
   echo("<p>Message successfully sent!</p>");
  } else {
   echo("<p>Message delivery failed...</p>");
  }
 ?>

This will never send emails to me although the feedback "successfully" is displayed. The code will work (email actually sent) however if I removed the inclusion of

$server = $_SERVER['HTTP_HOST'];

in the email body.

Very weird, it doesn't make sense ?

This is just a PHP page. I call this page from a browser !! Please try ...

UPDATE!! okay, Instead of using $_SERVER['HTTP_HOST'], I use a string "user.server.com" directly. AND, it did not work !! But, when I modified a string a bit, like "user.server.com.us", it works !! So basically, the mail server filler its own reference to its domain, not sure why its doing this...

Answer 1

Some spam servers grade your message as 'spammy' for urls in the body. Unfortunately you'll be hard-pressed to find a more specific error message with mail() unless you have access to the sender and recipient's mail server logs. Give SwiftMailer or another PHP Mailing library for better support.

Answer 2

When using mail() function you are required to specify 'From' header. Please refer to this documentation page, look for 'additional_headers' parameter's Notes section.

So your mail() call will look like this:

mail($to, $subject, $body, 'From: some.guy@example.com');

Answer 3

Of course you don't receive it because there these days all major webmails use anti spam filters and probably your message is detected as a spam. The solution is to specify exactly your email for $from variable, if you don't specify your real email your message is detected as spam.