imap_open - undefined function ... help!

[MCrosbie]

Hi there I got this error:

[!--quoteo--][div class=\'quotetop\']QUOTE[/div][div class=\'quotemain\'][!--quotec--]Fatal error: Call to undefined function: imap_open() in /home/nxc/public_html/automail.php on line 25[/quote]

with this code:

[code]
$server = "9thdesign.net";
echo "Server: ".$server."
";

$user = "support@".$server."";
echo "User: ".$user."
";

$pass = "supportpass;
echo "Password: ".$pass."
";

$conn = imap_open("\{$server/imap}INBOX", $user, $pass)
or die("Connection to server failed ERROR: ". imap_last_error() ."");[/code]

Any ideas why?

Cheers,

Michael