My inquiry started when my little sister asked how she could set up an auto-response on ONLY one of her email accounts, but not all of them. Nicole, who is scheduled to be induced this week (very excited), has a master (or centralized) gmail account which she uses for her personal email, work email and other emails via the "Multiple Inboxes" feature within gmail.
Although Multiple Inboxes is one of the best way to get a single view into all your email accounts, this configuration won't play nicely with the "vacation response" option (mail>settings>general) that comes standard with Gmail (not a labs feature). The issue is that the vacation response is generated for ALL emails hitting your inbox.
NOTE: The one exception that you can configure it to "Only send a [vacation] response to people in my Contacts" under mail>settings>general tab... and this exception doesn't solve for the multiple inbox configuration.
So during my research I figured that the only way to set this up was through a two step process...
1) that requires uses to enable "canned responses" in google labs for gmail (mail>settings>labs tab) and
2) the use of "filters" (mail>settings>filters tab).