There are a number of ways you could go about this. The first, and least recommended is to use a regex something like this:

use strict;
use warnings;

#throw away first two lines
<DATA>;
<DATA>;

while (<DATA>)
  {
  chomp;
  next if ! defined $_ or ! length $_;
  my ($date, $time, $recip, $subject, $send) =
    /\s*([^\t]+)      #date
      \s+([^\t]+)     #time
      (?:\t[^\t]+){5}\s+  #Skip 5 fields
      (\S+)           #Recipient
      (?:\t[^\t]+){10}\s+  #Skip 10 fields
      ([^\t]*)\t      #subject
      ([^\t]*)        #Sender
    /x;
  
  print "$date, $time, $recip, $subject, $send\n";
  }
[download]

which generates

2005-9-10, 0:0:16 GMT, Someoneg@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, EX:/O=org/OU=Site/CN=RECIPIENTS/CN=Auser
2005-9-10, 0:0:16 GMT, c1r3ai4g@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, -
2005-9-10, 0:0:16 GMT, c1r3ai4g@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, -
2005-9-10, 0:0:16 GMT, c1r3ai4g@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, -
2005-9-10, 0:0:17 GMT, c1r3ai4g@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, Auser@Domain.name
2005-9-10, 0:0:17 GMT, c1r3ai4g@aol.com, Fw: Hey Ugly line expansion a
+nd re-offer, Auser@Domain.name
[download]

However using a regex for parsing csv data such as this can be very difficult due to managing quoted data. It is generally better to use something like Text::CSV::Simple.

Yet another option, if you are comfortable with databases, is to use DBI to wrap your file and manage it as a database.