You want a hash not an array for @saw. 
#!/usr/bin/perl -w

use strict;

my @emails = qw/mgr@acme.net
ipadm@acme.net
abuse@acme.net
mgr@acme.net
ipadm@acme.net
abuse@acme.net
    /;

my %saw;
@emails = grep(!$saw{$_}++, @emails);

foreach (keys %saw) {
    print "$_\n";
}

[download]

grep 
grep> cd pub 
grep> more beer

In reply to Re: Problems with Comparing Arrays by grep
in thread Problems with Comparing Arrays by dru145

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