for my $entry(@data){
   print sprintf("%-*s %-*s %-*s<<\n",$len_vorname,$entry->[0],
                                      $len_nachname,$entry->[1],
                                      $len_domain,$entry->[2]);
}

#!/usr/bin/perl

use warnings;
use strict;

my @data;
my $file      = 'mailbox.txt';
my $delimiter = '\s{2,}|\t|\\';
my $columns   = 2;

open(my $fh,'<',$file) or die $!;
while(my $line = <$fh>) {  # alles was unten in __DATA__ steht symbolisiert eine Datei
   chomp $line;
   my @array = (split(/$delimiter/,$line))[0..($columns-1)];

   foreach (@array) {
       s%^\s+%%g; # fuehrende und
       s%\s+$%%g; # abschliessende Blanks entfernen
   } # foreach
 
   push(@data,[@array]);
} # while
close $fh;

my $format = '';

for my $i(0..scalar(@{$data[0]})-1){
   my $max = find_longest(map{$_->[$i]}@data);
   $format .= '%-'.$max.'s ';
}

for my $entry(@data){
   print sprintf($format . "<<\n",@$entry);
}

sub find_longest{
   my $longest = 0;
   for(@_){
       my $length = length($_);
       $longest = $length if($length > $longest);
   }

   return $longest;
}