The following /etc/sudoers entry worked under Mac OS 10.7, but prompts for a password under 10.8:
username ALL=NOPASSWD:/usr/libexec/dovecot/deliver
I assume that Apple upgraded to a newer sudo; the version under 10.8 is 1.7.4p6, which still doesn't seem to be that up-to-date. Unfortunately, every site that appears to have a changelog for sudo is unreachable right now.
Could somebody point me to the correct syntax to allow user username to run deliver via sudo without providing a password on Mac OS 10.8? This change is preventing any email from being delivered via procmail, which is not 100% ideal!