sendmail configuration help

I need help configuring sendmail on my linux/apache server. i had one domain on there already and mail was working fine. i just added another domain (with a different ip address) and set the MX records for it, and created the user accounts on the server. i have also configured outlook with the accounts for the new domain. ***the problem is that i can receive emails to these accounts, but i can't send emails to the outside world (i CAN send to domains on the server though).*** when i try to send an email from an account under the new domain i get this error: ***Relaying denied. Proper authentication required.*** in the Outlook settings i have the box checked for "My outgoing server (SMTP) requires authentication." so i'm assuming there are some relaying settings within sendmail that need to be set for the new domain. i just don't know where. this should be a pretty tiny job for someone who really knows what they are doing with sendmail. please don't bid unless you're an expert in sendmail. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform apache redhat linux php 4.2.2