please check if that code produces that output:

lanx@nc10-ubuntu:~$ perl
my @systems=qw(SERVER1 SERVER2 SERVER3);
foreach my $system (@systems) {
    print "Now powering on $system:";
    print "\t\t[DONE]\n";
}
__END__
Now powering on SERVER1:        [DONE]
Now powering on SERVER2:        [DONE]
Now powering on SERVER3:        [DONE]
lanx@nc10-ubuntu:~$ 
[download]

Otherwise try to isolate the bug, eg dump \@systems and check special vars.

UPDATE:

If you click on the download link of my code you will see that my example has real tabs where yours has a list of blanks. Your not posting the real output.

UPDATE:

do your servernames really have the same length?

lanx@nc10-ubuntu:~$ perl
my @systems=qw(SRV1 SERVER2 SERVER3);
foreach my $system (@systems) {
    print "Now powering on $system:";
    print "\t\t[DONE]\n";
}
__END__
Now powering on SRV1:        [DONE]
Now powering on SERVER2:        [DONE]
Now powering on SERVER3:        [DONE]
[download]

if not better try using printf or formats