my %mail = (
		To   => 'mail@there.com',
		From => 'from@there.com'
	);

if($old ne $curr){
	$mail{'Subject'} = "Subject A";
	$mail{'Message'} = "Subject A message here";
}
elsif($var eq $job){
	$mail{'Subject'} = "Subject B";
	$mail{'Message'} = "Subject B message here";
} else {
	$mail{'Subject'} = "Subject C";
	$mail{'Message'} = "subject C message here";
}

$mail{smtp} = $mailserv;

sendmail(%mail);