Another trick that I am fond of would be to do the actual vmstat within an open:

open (VMSTAT, "/usr/bin/vmstat 1 10|");
while (<VMSTAT>) {
  next if ($_ !~ /^ \d+/);
  (undef,undef,undef,$pos5,$pos6) = split; # CountZero++
  push @mylist1, $pos5;
  push @mylist2, $pos6;
}
[download]

Also, I'm not familiar with MIME::Lite but I'd look at creating the message without actually creating a temporary file since you just get rid of it anyhow.

JK