The recursive chown to postfix at the end of the entrypoint also takes the queue directory itself and pid/, which Postfix keeps owned by root; postfix-script logs warning: not owned by root for both at every start. They are handed back to root after the chown, as public/ and maildrop/ are handed back to postdrop. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>