Hey!
The best way to check your email spam status is by using Google Postmaster Tools—it gives pretty accurate insights into your email reputation.
You can also just do a quick manual test by sending emails to a few friends and seeing if they land in the inbox or spam. That works too!
Also, I saw you mentioned that 8 of your email domains are gone. For that, I highly recommend checking out Allegro.co—it’s super powerful. In my experience, they can revive a bad domain in just 2–3 weeks. Haven’t seen anything else work that well.