One of the selling points of Linux is that older PCs that cannot run the latest version of Windows can often be used for Linux. While this is true, there are other factors affecting the choice of a PC for a critical role.
Spam filtering is CPU-intensive. However, it is rarely worth paying a premium price for a fast processor, which costs more per processing unit than the older slow processors. High-speed disks are not required unless a multiple-CPU machine is highly loaded. Disk I/O is relatively low for spam processing. The disk space usage for an email gateway will be low. The server software installation can be less than 1 GB, and little additional space is required, unless the main email server is down for a period of time, in which case additional spool space will be required.
Older PCs often have no hardware support. If a component fails, there may not be an engineer call-out available, and a suitable replacement part may not be available for several days. Older...
