Outlook time issue

We are having a problem with the time stamp on incoming emails.
For instance i can send an email to a co-worker and when they reply it shows that they replied before the original message was sent.
This also happens when we recieve email's from outside sources.

We have our own domain and email server, the server is located at a 3rd party site.
We are all running Outlook some have 2000 and some have 2003. Our virus and spyware checks are current.

I am out of ideas, i hope that someone might be able to help me.

Thanks

 

Thanks,
From my research that's what i thought it was but i wanted to hear it from someone else. i've contacted the person who is administering our email server and hopefully i will be able to resolve the problem