Automating Instagram DM outreach

I need to send a message to 3k brands.
I will not be sending brands a generic outreach message - it'll be a unique personalized question about their company, and I can say with certainty that most will reply.
How should I go about automating this outreach?
Is simple browser automation enough? Considering brands will reply to us, what is the max sending/day rate you recommend per account? Proxies? Any other advice?

Go with DM Outreach Service, its availaible in marketplace. You can send 3k DMs with 3-5 Accounts in a Month, Make sure to customise the accounts completely which will be sending the DMs.