My problem with a catch-all was that there is a lot of spam that gets send to various common email addresses such as "admin". Do you maintain a blacklist for your users?

I have a regular expression set as a username in my database of email addresses. (spoilers: it's just somesalt.*."2 or 3 characters" so for example [email protected]). So I can sign up to any random website by just entering salt.thatwebsite.tld@me as my email. That's the zero-configuration part. Honestly, this is worth paying $9/year for imho :P

The personal and and professional mail together is simply internally forwarding my professional mail to the same imap instance but a different folder :P. It's mostly future-proofing on my part. If I were to get/manage a different domain-name (say a gaming guild or business venture) I could merge those too and not have to set-up 27 different accounts in my email client.