Windows r2 2012服务器 - PHPmailer问题

Question

I am running php / mysql on an IIS server on Windows 2012 R2 server . I am using phpmailer to send out emails from the application that is build on that server . I am used to working on phpmailer though i don't have a thorough expertise on the IIS servers.

When i try to run the program , below is the error that i keep getting .

Could not instantiate mail function.

Below is my code :

$mail->SetFrom('ip address of the server'); //i am using the IP address as the server doesnt have a domain name or an email id

    $mail->Subject    = "TEXT";

    $mail->AddAddress('Email address', ""); //changed in this case 

    $body  = "TEXT 5";

    $mail->MsgHTML($body);
    $mail->AddAttachment("app1.pdf");
    if($mail->Send())
    {
        echo "sent";
    }
    else{
        echo $mail->ErrorInfo;
    }

If i run it on any other server with a genuine email id of that server ,it works fine . The issue with this server (Windows r2 2012) is that it does not have a domain name or an email id , just the IP address .

Would be great if someone could advice how to go about handling this issue .

Thanks in advance.