This program is a wrapper for the prog mailer in sendmail. It does shell
meta character masking and restricts the list of executables to those found
in /usr/libexec/sm.bin.
The default sendmail.cf file does not use this tool, however you can enable
it by either changing /bin/sh to /usr/libexec/smrsh or adding the line
FEATURE(smrsh) into your sendmail .mc file and rebuilding your .cf file.
For more info, RTFMP.
