This is a question that only you can answer. It really depends on your environment and what expertise you have in-house. It also depends on what third-party products you use (backup, virus scanning, spam control, monitoring, etc.). If you have the expertise and your products work with Linux, then there is no problem with choosing it as your OS. It is a good, viable choice for small to mid-sized servers. It scales as well as Windows 2000 in most cases, but it cannot scale with the big Unix flavors.
This was first published in April 2003