If you have no FTP capability, the same postings will tell you how to retrieve Simtel files by e-mail. Its best feature is a really-fast small preview window, which is great for searching through lots of image files. The user interface is clunky but functional. The Swiss army knife of DOS viewers. Does almost everything, but a bit intimidating for newcomers.
User interface is much improved over early versions, but still awkward in places.
Requires 386 or better. A well-done viewer and image converter for many image formats. Installation is simple, and the on-line documentation is very good. JPEG loading is a bit slower than the above viewers, though. Current version is 3.1f.