LOL...I think 87% of the posts here are an elaborate scheme to sell their products!
Bounce rates might be an issue with the way you are sending mail. If you are sending from your own IP addresses (and domains), I believe there's a fair amount of prep work you need to do with warming up IPs, DMARC, SPF and DKIM settings.
With that said, you may want to scale way back on sending emails until you 'warm up' your IP addresses. I think that you may screw your up domain's ability to send email without being considered spam, if you are not extra careful.
You may already know all of this...
I looked at a few more of your posts. When you get some time highly suggest you look into sendy (
https://sendy.co/). There's a lot of technical stuff here, but you can probably manage it.
You can use a service at outrageous prices...Or roll your own with sendy. From what I understand 'cold email marketing' has many rules that didn't exist 2-5 years ago. I too, am gearing up for some serious cold email marketing campaigns.
If you've got the money to spend I'd certainly look into getting some paid help from here or fivver or whatever.