> Anyone running Unbound DNS can also do this Yep. Just checked the docs for that and “cache-min-ttl” is a thing. For those unfamiliar, unbound is a pretty com

> Anyone running Unbound DNS can also do this Yep. Just checked the docs for that and “cache-min-ttl” is a thing. For those unfamiliar, unbound is a pretty common resolver: it is the default for most BSDs and things based on them (such as pfSense) and used by the popular PiHole and its forks. How common it is to use this setting I can't comment on. > Some versions and distributions of Java do all manor of odd things with DNS including ignoring TTL's This at least is less of an issue if all you are futzing with the DNS for is services intended to be consumed by a web browser: if common browsers and DNS resolvers behave OK then you are good, if someone consuming your stuff through their own code hits a problem they can work around it themselves :) It goes without saying that only a fool would play trick like this for email as that is already a mountain of things that can be easily upset by anything off the beaten track. EDIT: Also, yep, people are using the setting in their normal environments: https://stackoverflow.com/questions/21799834/how-to-determine-a-proper-value-for-cache-min-ttl https://stackoverflow.com/questions/21799834/how-to-determin... (that person currently having it set to 30 minutes)