Advanced Postfix configuration SPF DKIM

Looking for advanced experienced Postfix administrator in configuring our Postfix SMTP server for email marketing newsletters and configure the best delivery options to avoid getting blacklisted with major mail servers (yahoo, gmail, hotmail etc). We have a Fedora 13 linux server used to send a large list of email newsletters. Postfix is already installed and working basically for sending bulk email generated in the same server. We want to install 2 more instances of Postfix to send email using 2 more virtual IP addresses that we have configured on the server to be used for 2 more domain names, besides the main IP address that is used for a different domain name. (That would be 3 different Postfixes) Emails sent by each domain name must be identified by its own IP address. 3 IP addresses for 3 domain names. So the job includes configuring POSTFIX to accept email delivery from other locations (relay). Enabling a list of permitted IP addresses as the first choice, and by authenticating username and password as the second choice. Apply the best configuration options for email delivery of 300.000 emails per day per IP, we will probably be using Interspire Email Marketer on the same server or on another server and send through this server. Check and adjust: configuration of mailserver, SPF, domain keys DKIM for the 3 domains hosted on the server. Since we host the DNS zones in another server, you must provide us with the information to do what is needed regarding this. Enable the additional 2 postfix installations to be managed through webmin. The server is only used to send email for these domain names, the email accounts for these domains are already configured on google apps (gmail's free domain email accounts) Important: they must be 3 independent postfix installations