The plugin never guesses from traffic, logins or disk usage. It only looks at public DNS: where each domain's website and mail actually go.
An account is active, and never listed, if any one of its domains (main, addon, parked or subdomain):
- has a website (A record) pointing at one of this server's IP addresses, or
- has mail (MX record) pointing at this server, or
- uses a trusted nameserver, such as Cloudflare's.
It is inactive only when every domain fails all three: the domains point elsewhere, don't resolve, or have expired.
These do not make an account active: logging in, files on disk, databases, FTP, or a domain that merely exists in the panel.
If a check can't finish (a lookup times out, the domain list can't be read), the account is treated as active for safety. Nothing is ever suspended or removed on an incomplete check.