Mail Relayer Question

is php mail() a relayer?

[CodeMonkey]

Okay,
When I send mail out via the mail()function, is it considered a relayed message?
I guess, I don't really understand what a relayed message really is.
I think I've got the headers right:
$headers = "MIME-Version: 1.0\n";
$headers .="Content-type: text/html; charset=iso-8859-1\n";
$headers .= "X-Mailer: PHP4\n";
$headers .="X-Priority: 3 (Normal)\n";
$headers .="From: The Name<$femail>\n";

The thing is, one of my customers has a large opt-in base. When he mass mails them, they show up in my WHM stats as relayed messages.
This worries me, as some of the messages are being rejected because they were relayed.

Thanks for your help,
Jay

[Knowles]

CodeMonkey welcome to WebmasterWorld!

Do you know what your settings in your php.ini are? Is it possible that it is using a remote mail server which would cause this to be a relayed msg? I am shooting in the dark here.

[CodeMonkey]

Thanks Knowles,
Here is the line from the php.ini file:
sendmail_path = /usr/sbin/sendmail -t -i ;

I assume this means that it is using the local sendmail program?

[Philosopher]

I'd like to know the answer to this as well as I'm looking at doing some opt-in mailings using this function and don't want things to get rejected.