Your errors tell part of the story, and it looks like you know better, too :)
You have
$mailHTML::MIME::Lite->attach( Type =>'text/html; charset="iso-8859-1"
+',
Data => '<b>Brought to you now!</b>',
);
which should be
$mailHTML->attach( Type =>'text/html; charset="iso-8859-1"',
Data => '<b>Brought to you now!</b>',
);
precisely for the same reasons you used it as
my $MIMEmail = $mailHTML->parse("$URL");
towards the end of your script. The token (is that the right word?)
$mailHTML has all the methods "embedded" -- you don't need to try to specify which parts of which inherited interfaces you want to play with; it has them "natively" so to speak.
This presupposes that the ::Lite extension does properly inherit, of course.