Complete Linux Email Server

I need to have an email server setup on a dedicated server I have with a web host. Its running the lastest stable debian and I have full root access. What I need setup is Sendmail/Exim/... to send emails for several different domains 4+... and i also need a webmail client installed to check mail for these domains... right now i have exim setup as my MTA but its obviouslly not setup right because it puts all mail i send from my server to my yahoo email account in the bulk folder... bascially i need some one to come in and make email sending work perfect ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) 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 Linux (latest stable Debian)