use Mail::Send ();

my @users = qw( bob carol ted alice );

while( 1 ) {
  for my $user ( @users ) {
    my $msg = Mail::Send->new( To => $user, Subject => "So, whatcha doing?" );
    my $fh = $msg->open;
    print $fh "Please let me know.\n"
    $fh->close();
  }
  sleep( 360 );
}