PHP Mail Not Sending

[entranceexam2018]

$toMail = "[email protected]"; //this works - I get the email at my Gmail.com
$toMail = "[email protected]"; //this doesn't - I get nothing

mail($toMail, $subject, $message, $header);
This Is the the script which i use in my cpanel from which i can access and my mail and also receive it.

 

[cPanelMichael]

Hello,

Could you let us know what you see in /var/log/exim_mainlog when the message delivery fails?

Thank you.