I just updated to mail-mta/courier/courier-0.48.1 It overwrote all files in /etc/courier. I think that directory should be placed under configuration protection for dispatch-conf / etc-update. Reproducible: Always Steps to Reproduce: 1. 2. 3.
/etc/courier is covered by the overall protection of /etc. You would have to specifically add /etc/courier to CONFIG_PROTECT_MASK to make it *not* protect /etc/courier. Otherwise, its already protected. By default. Unless of course you gave a "-5" while running etc-update.