Zimbra 9 OSE configuration of 12 fix IPs for 12 Domains for outgoing Emails for rDNS registration

I am looking to hire someone to do a Zimbra 9 OSE configuration on Linux to set up 12 fixed IPs for 12 domains for outgoing emails and rDNS registration. The rDNS registraition is not part of this task and will be done by us. No additional services or third-party applications will be installed to make this configuration successful. As such, I am looking for an experienced Freelancer with a good background in Linux and Zimbra who is able to provide this service. The successful Freelancer should be able to implement the configuration as quickly and efficiently as possible.