testmxlookup(1) on Linux
The text c24ad119bbee, as Debian 13 (Trixie) shipped it. The page shows this text now.
Look up mail servers for a domain
Flags it lists
-
--dnssec -
--sts -
--sts-cache-disable -
--sts-cache-enable -
--sts-expire -
--sts-override -
--sts-purge -
--udpsize