but it is not working as expected

Alas, that is an insufficient description of the problem as I am sure on re-reading your post you will agree. You've given no sample data, no sample output, no error messages, no indication of what sendMail() might be or where it has been loaded from. The only possible advice one could give at this point (other than to suggest you provide an SSCCE) is to check everything.

Pretty much this/How do I post a question effectively?. Task::Kensho::Email.

#!/usr/bin/perl

use strict;
use warnings;
use MIME::Lite;

my $FROM = '"Senders Name" <youremail@email.com>';
my $TO   = 'destination_email@email.com';
my $CC   = 'second_destination@email.com';   # You may leave this blan
+k
my $SENDFILE = 'file_to_send.txt';

my $MAX_EMAIL_LENGTH = 1000000;  # Don't send email if it's too large

my $DATA = ReadFile($SENDFILE);
$DATA = pack('u', $DATA);        # Uuencode file contents
length($DATA) <= $MAX_EMAIL_LENGTH or die "\nThe email shouldn't be la
+rger than $MAX_EMAIL_LENGTH.\n";

# Send email
my $EMAIL_SUBJECT = "UUEncoded File";
my $HTML_MESSAGE = '';
my $TEXT_MESSAGE = "Here is your file:\n\n" . $DATA;
my $STATUS = SendMail($FROM, $TO, $CC, $EMAIL_SUBJECT, $TEXT_MESSAGE, 
+$HTML_MESSAGE);

exit;

######################################################

# Reads an entire file in raw mode and returns the contents as a strin
+g.
# Usage: STRING = ReadFile(FILENAME)
sub ReadFile { my $NAME = shift; (-e $NAME && -f $NAME && -s $NAME) or
+ return ''; my $DATA; open my $FILE, '<:raw', $NAME or return ''; { l
+ocal $/; $DATA = <$FILE>; } close $FILE; return (defined $DATA) ? $DA
+TA : ''; }

# The SendMail() function sends an email with an attachment. Returns 1
+ on success or 0 on failure.
# Usage: INTEGER = SendMail(FROM, TO, CC, SUBJECT, TEXT_MESSAGE, HTML_
+MESSAGE)
sub SendMail
{
  @_ == 6 or return 0;
  my ($From, $To, $Cc, $Subject, $TEXT, $HTML) = @_;
  my $EMAIL = MIME::Lite->new(
           From => $From,
             To => $To,
             Cc => $Cc,
        Subject => $Subject,
           Type => 'multipart/mixed');

  # Add text portion.
  $EMAIL->attach(
           Type => 'text',
           Data => $TEXT);

  # Add HTML portion.
  $EMAIL->attach(
           Type => 'text/html',
    Disposition => 'inline',
           Data => $HTML);

  $EMAIL->send;
  return 1;
}
[download]

How is this mess better than the examples in the synopsis of the module docs? Terrible error handling btw.