foreach my $message (@{ $messages }) {

    foreach my $message (@$messages) {

        my $content_type = $message->{'content_type'} || 'text/plain; charset="UTF-8"';

        $message->{is_html} = $message->{content_type} && $message->{content_type} =~ /html/i;

        my $is_html      = $content_type =~ m/html/io;

        $message->{'is_html'} = $is_html;