Email Parser does not require a very powerful PC to run. It typically consumes 100-200MB of RAM and the internal database is limited to 500MB of disk. Older entries are removed automatically when it reaches the maximum size. The installation size (the files under C:\Program Files\Email Parser) is around 800MB.
Generally speaking, if the machine meets the minimum requirements to run Windows, Email Parser will work fine.
The minimum supported Windows build number is 17063 (see the list of Windows build numbers). This includes the following Windows releases:
These Windows versions are not supported:
Email Parser is able to run on a machine with 2GB of RAM and a single-core CPU. Of course, if you need to process your emails faster, specially if you process attachments, a more powerful machine is recommended.
If you plan to run Email Parser on a VPS (virtual private server) or on any virtual machine and are concerned about the hosting costs, pick the most lower-end option. Most of the times it will run Email Parser just fine.