Is it possible to send the DOS print jobs via e-mail?
Yes. If on your machine some special "virtual printer" is installed (for example Adobe Acrobat Distiller), then you've simply to choose that printer as destination in the Printfil's configuration dialog. When Printfil will send the DOS print job to that printer, the standard driver dialogs will be shown, allowing you to automatically e-mail the job.
Alternatively, you can export the DOS print job on a PDF file through the "Printfil" virtual printer (instructions are included in the manual) which allows even automatically sending the job by using your favourite e-mail client, with or without user intervention.