$ cat if-mail.pl 
#!/usr/bin/perl
exit 0 unless (my @lines = <STDIN>);
open(my $mail, "|-", join " ", "/usr/bin/mail", @ARGV) or die $!;
print $mail @lines;
$ LC_ALL=C ./if-mail.pl root@localhost -s "do not run echo; touch ~/zzz && ls ~/zzz - it does not make sense"
TEST
^D
ls: cannot access -: No such file or directory
ls: cannot access it: No such file or directory
ls: cannot access does: No such file or directory
ls: cannot access not: No such file or directory
ls: cannot access make: No such file or directory
ls: cannot access sense: No such file or directory
/home/aitap/zzz
$ ./if-mail.pl root@localhost -s "try running echo *"
TEST
^D