Me again, Another problem I've found since doing my yum update is that EXIM is now showing the following error, on startup, and repeatedly in main.log [root at ollie2 ~]# exim -bt localpart at example.com 2016-05-06 09:27:04 WARNING: purging the environment. Suggested action: use keep_environment and add_environment. ............... Googling says that to fix this all I need to do is add keep_environment to exim.conf. What I'm struggling to find out is why it's suddenly needed and what the effects are