You've got to be really careful when you set your Out of Office as shown in this great example from a council in Swansea.
When officials asked for the Welsh translation of a road sign, they thought the reply was what they needed.
Unfortunately, the e-mail response to Swansea council said in Welsh: "I am not in the office at the moment. Please send any work to be translated".
They've since taken it down :)
The BBC Website has more details :)