Your post is extremely misleading and full of false information.
I’ve been using a small VPS (sub $10/month) to self host mail for at least 10 years, and I’ve migrated hosts a few times without issue.
I’ve even migrated to a “polluted” IP on a different provider and getting that removed from RBLs took a couple of emails and the entire process honestly took less than a week.
I’ve been using a small VPS (sub $10/month) to self host mail for at least 10 years, and I’ve migrated hosts a few times without issue.
I’ve even migrated to a “polluted” IP on a different provider and getting that removed from RBLs took a couple of emails and the entire process honestly took less than a week.