mail(): SMTP server response: 550 The address is not valid error on hmailserver

I am getting this error despite configuring php.ini to a valid send_from address. I know it is valid because it works when I send it from squirrel mail but when sending mail in php it will just not work. the invalid address presumably refers to the send_from address. so I can't see how it can think it's wrong. here is the php code:

$email="tobiasvogel1@googlemail.com";
$subject = "Your New Password";
$from="admin@dayshare.local";
$message = "Your new password is as follows:

xxxxxxxxxxxxxxxxxxxxxxxxxxx

This email was automatically generated.";

      if(!mail($email, $subject,$message,$from)){
         echo ("error");
      }else echo "success";

在 php.ini 中:

SMTP = localhost

sendmail_from = admin@dayshare.local

<?php
mail('tobiasvogel1@googlemail.com','Test Email','This is a test email.',"From: tobiasvogel1@googlemail.com");
?>