We had a need to create an e-mail account in Zimbra that would always generate an automated response to incoming e-mails. So we activated the OutOfOffice functionality (or “Vacation Mode” as some people prefer to call it). This is great, and you do have some control from the ZWC (Zimbra Web Client) user interface.
The “problem” with the OOO functionality is that it is designed for human interaction. So, in an attempt to be somewhat “intelligent”, Zimbra will remember to whom it has sent an automated response message, and if a second message is received within nn time, it will not send another one. This makes sense, if I have sent an e-mail to John Doe, and Mr Doe is on vacation, I probably know this to be true even if I send him another message within a few hours or days. So I don’t want a second automated response.
We wanted it to send an automated response every time it received a message, zmprov to the rescue!
As the ‘zimbra’ user, from the CLI prompt, enter:
zmprov ma email@example.com zimbraPrefOutOfOfficeCacheDuration <value>
The default <value> in our installation was 7d, presumably that means seven days. So I set it to ‘1s’ and anyone sending e-mail to firstname.lastname@example.org now gets an automated response, even if they send several messages within a short period of time.