mail is not sent from network PC's

[dr_wack]

hi frnds

my email code works fine on my own system...but when i try to send mail form other network system ...it doesn't send mail nor give any error.
why this happening ..do i need to change any configuration in php.ini file???
i am using this code

$email_subject = $POST['txtf_subject'];
$email_message = $POST['txta_reply'];

$email_to = $_POST['txtf_replyto']; // Who the email is too
$ok = mail($email_to, $email_subject, $email_message);

if($ok) {
echo "<font face=verdana size=2>The file was successfully sent!</font>";
} else {
die("Sorry but the email could not be sent. Please go back and try again!");
}

tell me plzzzzzzzzzzzzz
waitinggggg alootttt

[Frederick]

Some IP addresses my be getting blocked from using SMTP. This restriction is widely used for spam blocking within networks. Check with your network administrator to see if he/she has setup restrictions in this area.

[dr_wack]

how i can check it myself
as i myself has to find set all settings of smtp??

as u r saying

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Some IP addresses my be getting blocked from using SMTP. This restriction is widely used for spam blocking within networks. Check with your network administrator to see if he/she has setup restrictions in this area.

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