Check email addresses for bad syntax, typos in the domain (gmial.com -> gmail.com),
disposable domains, role addresses, duplicates and domains that do not exist or have
no mail server. No API key.

The Clojure version of the free checker at https://bouncelens.com/ - same results.
The only network calls are DNS-over-HTTPS lookups (Cloudflare 1.1.1.1) of each domain's
MX and A records. It never connects to the recipient's mail server, so it never confirms
that a mailbox exists: the best status is :unconfirmed.

  (require '[bouncelens.email-check :as ec])
  (ec/check-one "jane@gmial.com")
  ;; => {:status :risky, :did-you-mean "jane@gmail.com", :reasons [...], ...}