Why seek at all in this situation? Why not:

#!/usr/bin/perl  -w


# use strict;

my @messagesIn;
my $MAXSAVE = 12;

my $name = "Duane Wade";
my $subject = "My Career";
my $message = "No one ever thought I'd be this good.";

flock("messageTest.txt",2);
open(FROMFILE,"<messageTest.txt");
while (<FROMFILE> and $cnt++ < $MAXSAVE ) # just quit reading when you
+ have enough
{
    # chomp;  you put the line ending back when you write it so don't 
+bother taking it off
    push @messagesIn, $_;
}


close(FROMFILE);
flock("messageTest.txt",8);

open (TOFILE,">>messageTest.txt");
flock("messageTest.txt",2);
seek(TOFILE,0,0);

# shove your message at the start of the array
unshift @messageIn, "$name|$subject|$message\n";
# print TOFILE "$name|$subject|$message\n";

# my $counter = 0;
# while ( $counter < @messagesIn )
print TOFILE @messageIn;
# foreach (@messagesIn)
# {
#     print TOFILE;
# }
#
# truncate(TOFILE, tell(TOFILE));
flock("messageTest.txt",8);
close (TOFILE);

1;
[download]

That does what I think you're after.

Edit by castaway - replaced pre tags with code tags