Use libwrap.a for connects (V8.8 and above) tune with confENVDEF

Beginning with V8.8 sendmail, it is possible to use the libwrap.a library to validate incoming SMTP connections.

    Part I: Build and Install
    Chapter 2. Build and Install sendmail
    Chapter 4. Configure sendmail.cf with m4
    Part II: Administration
    Part III: The Configuration File