1 user can't send email to all recipients

[allwebnow]

I have 1 user that tries to send email and everything sends smoothly out of Outlook, but not all people he's sending to get his email messages. This is the only user I'm having problems with. I'm currently running my server based pretty much off of configserver's website docs and Chirpy's forums. If anyone can help me with this that would be great! I would love to have Config Server help with this but I need help now.

The user has all the setting correct in outlook ie. server requires authentication etc. and he can recieve just fine and send to some people.

I'm on the same server as he's on and I didn't even get an email from him.
I'm at a loss with this.

Here's the user's exim log when he tries to send:

2007-04-18 15:46:21 1HeG6f-0008Vc-1n <= user@domain.com H=(name) [216.230.84.66] P=esmtpa A=fixed_login:user@domain.com S=70758 id=007401c781f2$4845ef40$64016544@name T="Re: Subject"

Then nothing else...

[allwebnow]

The log should be like this I would think:

2007-04-18 15:46:21 1HeG6f-0008Vc-1n <= user@domain.com H=(name) [216.230.84.66] P=esmtpa A=fixed_login:user@domain.com S=70758 id=007401c781f2$4845ef40$64016544@name T="Re: Subject"
2007-04-19 12:09:41 cwd=/var/spool/MailScanner/incoming/14511 5 args: /usr/sbin/exim -C /etc/exim_outgoing.conf -Mc 1HeZCV-0004Ky-Nu
2007-04-19 12:09:41 1HeZCV-0004Ky-Nu => sentuser <sentuser@sendtodomain.com> R=virtual_user T=virtual_userdelivery
2007-04-19 12:09:41 1HeZCV-0004Ky-Nu => sentuser <sentuser@sendtodomain.com> R=boxtraper_autowhitelist T=boxtrapper_autowhitelist
2007-04-19 12:09:41 1HeZCV-0004Ky-Nu Completed


Or something like this.