Follow-up: I was using my own shell script for backup, and in prior versions I had found that the command
was the only one that worked for me on Ubuntu with Zimbra 4.5.x. However, it seems with the newer version something about the way sudo calls the programs blows them up. I created a test batch for the sole purpose of stopping and starting the services, and watched them fail.
sudo -u zimbra /opt/zimbra/bin/zmcontrol start
The alternate syntax:
did the job.
su - zimbra -c "/opt/zimbra/bin/zmcontrol start"
I will watch the cron'ed run tonight before declaring victory, however. . .