use Mail::Sendmail;

#variable declarations etc...

if ($old ne $curr) 
{
        my %mail = ( To      => 'mail@there.com'',
                     From    => 'from@there.com',
                     Subject => "Subject A",
                     Message => "Subject A message here",
                       );
        $mail{smtp} = $mailserv;

        sendmail(%mail) || die "\nProblem! $Mail::Sendmail::error\n";
}
elsif ($var eq $job)
{
    my %mail = (     To      => 'mail@there.com'',
                     From    => 'from@there.com',
                     Subject => "Subject B",
                     Message => "Subject B message here",
                       );
        $mail{smtp} = $mailserv;

        sendmail(%mail) || die "\nProblem! $Mail::Sendmail::error\n";

}
else
}
    my %mail = (     To      => 'mail@there.com'',
                     From    => 'from@there.com',
                     Subject => "Subject C",
                     Message => "subject C message here",
                       );
        $mail{smtp} = $mailserv;

        sendmail(%mail) || die "\nProblem! $Mail::Sendmail::error\n";

}