courier-authlib-base ignores BATCH=yes in the environment and asks questions, waiting.
pkg_delete: package 'courier-authlib-base-0.56' is required by these other packages
and may not be deinstalled (but I'll delete it anyway):
Warning: Removing user courier will also delete any
undelivered mail in the mail queue directories!!!
Do *not* do it if you're upgrading and would like
courier to continue trying to deliver this mail.
Matching password entry:
courier:*:465:465::0:0:Courier Mail System:/var/spool/courier:/sbin/nologin
Is this the entry you wish to remove? y
How-To-Repeat: 1. install courier-authlib-base-0.56
2. BATCH=yes portupgrade -P courier-authlib-base
Over to maintainer.