Hey there,
After reviewing your project description its clear that you want someone to configure a SMTP server that contains 700 IPs and you also need 700 different users.
I'm very experienced with System Administration, Network Administration, SMTP Server Configuration and Troubleshooting, SMTP Authentication(SPF, Dkim, Dmarc, rDNS), SMTP IP Rotation, SMTP IP/Domain Reputation, Email Marketing, Email Handling.
I'll be happy to help you with this.
Thanks in advance for giving the opportunity to working with you.
Have a good day.
Best Regards,
Serazum Munir.