#!/usr/bin/perl

use strict;
use warnings;
use MIME::Lite;
use File::Copy qw(copy);

my $dir = '/verzeichnis/';
my $file = $dir . 'tttt.txt';
if( -e $file ){
    my ($d,$m,$y) = (localtime time)[3..5];
    my $date = sprintf "%02d%02d%04d", $d,$m+1,$y+1900;
    my $new  = 'tttt' . $date . '.bak';
    copy $file, $new;
}
else{
    my $mail = MIME::Lite->new(
        From => 'any_address@domain.example',
        To => 'chef@domain.example',
        Subject => 'tttt.txt nicht da',
        Data => 'Gude Chef, tttt.txt ist nicht da!',
    );
    $mail->send;
} 

# [...]
if( -e $file ){
    my ($d,$m,$y) = (localtime time)[3..5];
    my $date = sprintf "%02d%02d%04d", $d,$m+1,$y+1900;
    my $new  = 'tttt' . $date . '.bak';
    copy $file, $new;
    unlink $file if -e $new;
}
# [...]