One recommendation if something does not work as expected and people claim that it should (be it positive or negative): as the creator, never ever say "sorry"!

One recommendation if something does not work as expected and people claim that it should (be it positive or negative): as the creator, never ever say "sorry"! This will help you to keep the 'correct mental direction', which is that YOU provide the additional value and the issue poster wants something from you. Also if you are the maintainer, put a warning to people with too strong words and throw them out of your mailing list if a second violation occurs. Also newer 'mailing lists' (like discourse.org) help here with flagging capabilities, edit buttons and more. Try to ensure that the discussion stays 'emotionless' and without sarcasm or if you allow it do so only with emoticons ;)