No, this retrofit code is for moving Mail to systems (V7, S3, etc.)
which don't have the job control facility of 4.1BSD or the new signal
mechanism of 4.2BSD. If VMUNIX is defined in the 4.2BSD Mail, it uses
the 4.2 signal mechanism for job control.
Guy Harris
{seismo,ihnp4,allegra}!rlgvax!guy