Out of office replies, often termed "OOF" for Out Of Facility or "vacation auto-responders" are those automated replies to email when the recipient is away for some period of time. The returned message typically states that a) they're away from their office/home/whatever and won't be checking email, b) the dates for which that will be the case, and hopefully c) an alternate point of contact for the duration of their absence.

It seems like such a good idea. It can even be quite helpful if you're attempting to contact that person while they're away.

Unfortunately the problems with out of office replies have come to far outweigh the benefits.

MORE SPAM: You will get more spam if you set up an automated response. Automated replies validate that your email address is real. Spammers can note this, making your email address that much more valuable for spamming in the future.

LESS SECURITY: You've just advertised that your office, your computer and perhaps even your home might well be unoccupied for the duration of your absence. Anyone mailing you will find out that theft and burglary might well be significantly easier while you're gone.

EVEN LESS SECURITY: in a business setting it might well be doubly dangerous to send out of office messages outside the company revealing some of the companies inner workings. It might even be against corporate policy.

MORE NOISE: Depending on your mailer, your out of office message might get sent for every message you receive. If you're on a mailing list, or if someone sends you more than one message, that could generate a tremendous amount of redundant email "noise". In a worst case scenario, an out of office message can even cause a "mail loop" where automated replies bounce back and forth between two systems forever.

It's unfortunate but the bottom line is that using out of office replies is a great idea that's gone horribly, horribly wrong.

So what can you do instead?

Make sure that your important contacts always know who to contact if you're not available. Consider automatically forwarding your email to an alternate recipient or assistant while you're away. Use your voicemail to provide alternate contact information, or use your phone system to automatically transfer callers to someone who can handle the calls in your absence.

Finally, consider doing nothing at all. The repercussions are often much, much less than you might expect, and significantly safer than the unintended consequences listed above.