#!/usr/bin/perl
use strict;
use warnings;

my @MEDIA;
for (qx<sudo /usr/openv/netbackup/bin/admincmd/bpimagelist -A -media -
+hoursago 24>) {
  s/\|/ /;
  my ($Image) = split;
  for (qx<sudo /usr/openv/netbackup/bin/admincmd/nbemmcmd -listmedia -
+mediaid $Image>){
    next unless m/Media ID|Data Expiration/i;
    push @MEDIA, $_;
  }
}

if (@MEDIA){
  open(FF, "|/usr/bin/mailx -s 'Daily' ishonbackup.nar\@capgemini.com"
+) or die $!;
  for (@MEDIA){
    print FF $_ . "\n";
  }
  close FF;
}
[download]

What output do you expect from bpimagelist? You might want to run this in the debugger or add print statements to verify it.

s/\|/ /; ($image) = split; could be more easily written ($image) = split /\|/; although in either case I don't think it returns the value you want. split returns a list, so if you want one of the values you need to use a subscript.