The Print to File capability directs the print spooler service to redirect
the data stream from the printer driver to a file instead of the printer.
Since most printers these days implement a relatively complex language (with
instructions to position text on the page, print raster images, change
fonts, change colours, shade the background etc.), the output from the
drivers is not really human readable.
Essentially, all you can do with a file created by Print to File is "copy"
it to another printer of the same make and model as the printer driver that
originally created it. It might be useful for debugging printer drivers or
application/printer driver/printer problems, but is not really intended or
suitable for sending documents to other people.
You could open the file in Notepad and see what it contains, but I suspect
you will find it mostly giberish, unless you defined the printer to use the
(Generic) Generic Text driver. Even then, there will most likely be some
"special characters" (e.g. Form Feed, Carriage Return, Line Feed).
I suggest you send the file (document) in its original format, or open it in
some application (e.g. Internet Explorer, Word) and use that application to
save it in a suitable format (in IE or Word, click Files, Save As..., then
select the format you want from the "Save as type:" drop down list box).