Good target for spammers
My advice is to not use any Auto-Reply feature. Here's why:
For years I had faithfully changed my Out of Office message to let clients and others know exactly when I'd return, etc. I travel a great deal and I'm sure they appreciated the alert.
Then it dawned on me that all those spammers who were looking for "live" email addresses were also getting my auto-reply and adding my address to their "active" files.
I stopped using the auto-reply feature and within a few weeks it appeared as though my volume of spam was diiminishing. Not sure if there was a direct relation, but I'll never go back.
I keep a distribution list of people who "need to know" when I'm going to gone and send them an update when I leave. I also make consistent visits to Internet cafes when traveling to manage the email in a timely manner.