other features: live dns checks (spf, dkim, dmarc, mta-sts, tls-rpt, bimi), shows when a domain is ready to go from p=none to quarantine / reject, alerts and a monthly mail per client (both still experimental, sent through ur own smtp).
on my own ~40 domains it already found a customer's iot device sending failing mail en masse due to a misconfig, and a dkim break after a dns migration.
no login in the app, it sits behind a proxy (caddy / authelia / oauth2-proxy). license is agpl plus the the condition to notify clients about free nature of software. maybe will switch it to pure agplv3 later.

