Configure Linux server to prevent mail from being Spam in Yahoo

We have a Redhat linux server that uses exim to send mail. We need some help to examine or change settings on the server to reduce the chance that mail will be sent to Yahoo spam folders, such as setting up reverse DNS or following the tasks on this page: [login to view URL] We are using Domain Keys, and this problem still happens. Your job is to help fix this issue, but it may not be possible to fix 100%. We will only give remote access to the server via TeamViewer. ## 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 Redhat linux