I have on occasion gotten an “out of office” message from someone, usually not a close friends, but some business contact.
While I appreciate the answer, there is some risk in doing this.
There are spammers who specifically send out messages with just one line of garbage in it. While you may feel it is just a mistake if you have ever gotten one, I am sure they are doing it for a good reason:
For every email that doesn’t bounce back to them, they know they have a good email address. They are doubly sure of this if they get an “out of office” message in response to their spam.
Here is what I would do instead of an “out of office” message:
1) send out a email to your list (don’t spam) telling all your contacts you are going out of town
2) ask a co-worker to check through your email regularly and answer any legitimate inquiries with an “out of office” message.
3) set up remote access to your email and check it once every few days
Small thing, but might keep you off more spam sending lists.