I've been recently asked this question :
"I receive plenty of emails from candidates coming to corporate web site contact email, how can I automatically tell the candidates to apply on our Careers web site ?"
Following a number of steps, this is actually quite easy to create this productivity enhancement.
What you need is to:
In order to create a "canned response", it is required to install a gmail lab called "canned response". Go to your Gmail Labs setting
(link) and Enable this add-on
Then create your canned response: compose a new email with the response text, click on "Canned responses" and give it a name
Now you are ready for the last step : create a filter to send automatically this response when the email you receive contains the word "job"
From your Search box, click the right arrow to open the Advanced Search pop-up, enter the criteria to filter the appropriate emails and click "Create filter with this search". If you are not sure of your search criteria, you can test them by doing a search instead of a filter.
Then tell Gmail what to do with this emails : Skip the Inbox, Apply the label : Candidates, Send canned response Automatic Answer for candidates.
Click "Create filter" and you are done !