You're welcome! For your personal MX servers, the most cost effective solution I know of would be to have multiple domains and each domain have their own MX re

You're welcome! For your personal MX servers, the most cost effective solution I know of would be to have multiple domains and each domain have their own MX records and corresponding VM/server on its own unique provider to isolate them. Then ensure that people/businesses that are important to you know to contact you at 2+ email addresses/domains. If someone attacks one of your domains or MX servers, you can safely ignore the attack. These separate MX servers should be on different server/VPS providers in the event that the attack causes one of them to suspend your account. Your imap client can poll each of the servers/domains so that you get your emails.