PHP mail() w/ postfix problem in FC3

[Nathaniel Price]

I've been searching for the solution to this problem to no avail.

I recently did a clean install of FC3 on a server that was running RH8. 
There were a number of PHP scripts that I had configured to send out 
email for notices or passwords or the like. However, now that I've 
upgraded I can't send mail through the mail() command in PHP.

My problem is exactly like what I found here, but unfortunately that 
question was left unanswerd: 
https://www.redhat.com/archives/fedora-list/2004-December/msg06708.html

To summarize, I have no problem sending email via SMTP (one of the apps 
I run has the option to choose between using PHP mail() or using it's 
own SMTP client). Whenever I try to send mail with mail(), apache logs 
the following error:
    sendmail: fatal: chdir /var/spool/postfix: Permission denied
Postfix logs nothing.

I have checked the permissions on the /var/spool/postfix directory, and 
they seem to be in order:
    drwxr-xr-x  16 root   root    4096 Nov 23 05:11 postfix

php.ini is configured with:
    sendmail_path = /usr/sbin/sendmail -t -i

/usr/sbin/sendmail is a link to /etc/alternatives/mta which is a link to 
/usr/sbin/sendmail.postfix. All of these are world readable and executable.

This setting is not overriden anywhere else (tested with phpinfo()).

Does anyone know what's wrong and how to fix it? If not, is there a 
drop-in replacement for the sendmail command that will just forward the 
request to postfix via SMTP?

Thanks,
Nathaniel