I use the vacation module in the horde/imp webmail. Very slick, it allows users to start/stop the vacation(out of office) message and customize it. We use webmail 100% of the time, so having it built in is much easier for us. Plus the user-manager doesn't allow outside access--the majority of our users aren't in the local office. On SME 6.0 I had to alter the FTP access slightly for it to work--not a security issue for me, FTP is local only and the vacation module uses FTP on itself(localhost). If someone wants to take a look at it, just let me know. I'll create a 'test' account so you can take a look.