Dovecot + Postfix: Emails not being sent

[s0c0]

I recently setup an email server using dovecot and postfix on Fedora Core 3. I then configured my mail account on Windows 2000/Outlook 2003 using POP3. I ran the test on it and it verified it could hit everything (network connection, find smtp, find pop3, login to pop3, and send test email). I am able to receive emails from my yahoo account, but I get the following undelieverable error:
554 <*****@yahoo.com>: relay access denied

I am able to send directly from my fedora core 3 server though. I have sasl turned off for right now as well.

Suggestions? Please advise...

[adept]

you can close your mail relay function.
modify /etc/mail/access

[KeDruff]

Your server is not set up to accept outgoing mail from that computer. You need to turn this off or set up SMTP Authentication. Are you relaying from your server to your ISP's outgoing server? Or are you also running sendmail?

Cheers,
KD

[s0c0]

Okay, I figured it out. I added yahoo.com as the relay_domain in the /etc/postfix/main.cf file. I am using yahoo since my domain was registered through them and my MX record is located on their DNS.

I was then able to send from my win2k/outlook03 client to my yahoo acount. However the emails are showing up in the spam box and are taking a while to get there. I didn't time it, but it seemed like 30min.

So what can I do to resolve this?

To answer your question yes I did turn off SMTP authentication and no I am not running sendmail. I completely uninstalled sendmail and am only running postfix as my mta.