Delivery to gmail difficulties - repost

We require an email delivery specialist who specifically knows how to gain inbox specifically to Gmail, and also Yahoo, but our main issue is gmail Our database is 50% Gmail and 50% Yahoo, the emails are optin, with only a few bounces, we need a solution by the most experienced freelancer, i work in email marketing myself and as i understand the email providers are placing our mails in spam as we only have two domains (Gmail/Yahoo) so we need significant support and planning to gain maximum delivery for Gmail primarily and Yahoo secondly.