getting error Can't call method "mail" on an undefined value

Hi,

when i run my sendmail.pl script from xyz server, it runs fine and sends the email. but when i run from different server "abc", it give me following error:
Can't call method "mail" on an undefined value at line......

when i go to script that line contains: " $smtp->mail($senderEmail);  "

my script:

sub sendMail(){
    my ($message, $subject) = @_;
    my $smtp;
    print "Content-type: text/html\n\n";

    $smtp = Net::SMTP->new($mailServer); # connect to an SMTP server
    $smtp->mail($senderEmail);           # use the sender's address here
    $smtp->to($recipientEmail);          # recipient's address
    $smtp->data(); # Start the mail

 # Send the header.
    $smtp->datasend("To: $recipientEmail\n");
    $smtp->datasend("From: $senderEmail\n");
    $smtp->datasend("Subject: $subject\n");

    $smtp->datasend("\n");               # Send the body.
    $smtp->datasend("$message\n");

    $smtp->dataend();                        # Finish sending the mail
    $smtp->quit;                             # Close the SMTP connection -ab
}