Email Marketing In-House Server Setup

I would like to setup an in-house email marketing setup which is cost effective but also customizable to accommodate our changing needs. We typically send 250k-300k emails every day and face challenges with landing emails into gmail, yahoo & hotmail inboxes.

I am looking for a consulting proposition who can setup the above with required dkim,sfp and all related configurations for sending bulk emails which results in a higher open rate at the most competitive price.

Thanks,
Mohammed