Best Tools for Monitoring Cold Email Deliverability: Recommendations Needed

Hey guys! I have about 120 domains and 160 emails and will probably extend it further. I'm using Instantly for shipping emails. I'm now exploring tools that will allow me to monitor and improve the deliverability of my cold emails. What tools would you recommend to use? I am looking for the best cost/effect ratio. I'm currently looking into mailtrap and blacklist master. But there are many other options and I would love to hear your opinion on this. 🙂