Hello,
I have experience in mailing server configuration. I will do SMTP Configuration - Mautic SMTP Configuration then you can able to send millions of Emails as you required, i will setup mailing authentications SPF, DKIM, DMARC, RDNS, cName configuration - Domain Setup - Pop3 & Imap server - Cron job setup for automatic manual scheduled sending .I will configure mailing application on server and will pass all records that is SPF,DKIM,DMARC for good inbox.
Feel free to reach me i'll be waiting for your reply then we can discuss more.
Thank you