I always make a point of telling anyone in IT at whatever company I worked for that I appreciated what they did and knew it was a thankless job.
It's one of those areas where if you do a perfect job no one knows you're there and you're only high-profile when you screw up.
I've found over the years that they'll pay back that kindness ten-fold and often when you're in some sort of gnarly bind where time is critical.