[Mediawiki-l] SMTP configuration localhost

[Josh Joy]

Hi,

I have recently installed mediawiki, postfix with sasl and tls, and php pear
I configured my postfix server as a relay smtp, and tested it by 
invoking sendmail directly and was able to receive an email.
I then ran a test using php with a php page doing a submit and sending 
an email, this also worked.
For configuring mediawiki, for some reason I'm receiving errors. Here is 
the configuration I used in LocalSettings.php
## Begin Custom Configuration
$wgSMTP = array (
 "host" => 'localhost',
 "IDHost" => 'localhost',
 "port" => "25",
 "auth" => false
);

$wgEmailAuthentication = true;
$wgEnableEmail = true;
#$wgEnableUserEmail = true;

# Logging
$wgDebugLogFile = "/tmp/wiki.log";


The error message I receive when I create a new user on mediaiwiki and 
it tries to send a confirmation email is


    Login error:

Error sending mail: 1


Has anyone else experienced this? Thanks in advance.

Thanks,
Josh