use Tk;

$mw = new MainWindow;

my %vars;

foreach(qw/An: Von: Betreff:/) {
    $mw->Label(-text => $_)->grid($mw->Entry(-textvariable => \$vars{$_}));
}

$mw->Button(-text    => 'send',
            -command => sub { print "$_ ->> $vars{$_}\n" for keys %vars; })
     ->grid();

MainLoop();